diff --git a/core/include/flags.h b/core/include/flags.h
deleted file mode 100644
index 62a85a6b8c..0000000000
--- a/core/include/flags.h
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright (C) 2014 Freie Universität Berlin
- *
- * This file is subject to the terms and conditions of the GNU Lesser
- * General Public License v2.1. See the file LICENSE in the top level
- * directory for more details.
- */
-
-/**
- * @addtogroup  core_internal
- * @{
- *
- * @file
- * @brief       Misc flag definitions
- *
- * @author      Kaspar Schleiser <kaspar@schleiser.de>
- */
-
-#ifndef FLAGS_H
-#define FLAGS_H
-
-#ifdef __cplusplus
- extern "C" {
-#endif
-
-/**
- * @name Optional flags for controlling a threads initial state.
- * @{
- */
-#define CREATE_SLEEPING     (1)     /**< set the new thread to sleeping */
-#define AUTO_FREE           (2)     /**< currently not implemented */
-#define CREATE_WOUT_YIELD   (4)     /**< do not automatically call thread_yield() after creation */
-#define CREATE_STACKTEST    (8)     /**< write markers into the thread's stack to measure stack
-                                         usage (for debugging) */
-/** @} */
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* FLAGS_H */
-/** @} */
diff --git a/core/include/kernel.h b/core/include/kernel.h
index 4f948308df..4b22c39714 100644
--- a/core/include/kernel.h
+++ b/core/include/kernel.h
@@ -29,7 +29,6 @@
 #include "config.h"
 #include "tcb.h"
 #include "cpu.h"
-#include "flags.h"
 #include "sched.h"
 #include "cpu_conf.h"
 
diff --git a/core/include/thread.h b/core/include/thread.h
index da91b91a06..267857e42a 100644
--- a/core/include/thread.h
+++ b/core/include/thread.h
@@ -93,6 +93,32 @@
  */
 #define THREAD_PRIORITY_MAIN           (THREAD_PRIORITY_MIN - (SCHED_PRIO_LEVELS/2))
 
+/**
+ * @name Optional flags for controlling a threads initial state
+ * @{
+ */
+/**
+ * @brief Set the new thread to sleeping
+ **/
+#define THREAD_CREATE_SLEEPING          (1)
+
+/**
+ * @brief Currently not implemented
+ */
+#define THREAD_AUTO_FREE                (2)
+
+/**
+ * @brief Do not automatically call thread_yield() after creation
+ */
+#define THREAD_CREATE_WOUT_YIELD        (4)
+
+ /**
+  * @brief Write markers into the thread's stack to measure stack usage (for
+  *        debugging)
+  */
+#define THREAD_CREATE_STACKTEST         (8)
+/** @} */
+
 /**
  * @brief Creates a new thread
  *
@@ -113,11 +139,13 @@
  *
  * In addition to the priority, the *flags* argument can be used to alter the
  * newly created threads behavior after creation. The following flags are available:
- *  - CREATE_SLEEPING       the newly created thread will be put to sleeping state and
- *                          must be waken up manually
- *  - CREATE_WOUT_YIELD     the newly created thread will not run immediately after creation
- *  - CREATE_STACKTEST      write markers into the thread's stack to measure the stack's memory
- *                          usage (for debugging and profiling purposes)
+ *  - THREAD_CREATE_SLEEPING    the newly created thread will be put to sleeping
+ *                              state and must be waken up manually
+ *  - THREAD_CREATE_WOUT_YIELD  the newly created thread will not run
+ *                              immediately after creation
+ *  - THREAD_CREATE_STACKTEST   write markers into the thread's stack to measure
+ *                              the stack's memory usage (for debugging and
+ *                              profiling purposes)
  *
  * @note Currently we support creating threads from within an ISR, however it is considered
  *       to be a bad programming practice and we strongly discourage it.
@@ -229,7 +257,7 @@ const char *thread_getname(kernel_pid_t pid);
 /**
  * @brief Measures the stack usage of a stack
  *
- * Only works if the thread was created with the flag CREATE_STACKTEST.
+ * Only works if the thread was created with the flag THREAD_CREATE_STACKTEST.
  *
  * @param[in] stack the stack you want to measure. try `sched_active_thread->stack_start`
  *
diff --git a/core/kernel_init.c b/core/kernel_init.c
index b89e1ad22d..41ce102726 100644
--- a/core/kernel_init.c
+++ b/core/kernel_init.c
@@ -25,7 +25,6 @@
 #include "kernel.h"
 #include "kernel_internal.h"
 #include "sched.h"
-#include "flags.h"
 #include "cpu.h"
 #include "lpm.h"
 #include "thread.h"
@@ -95,12 +94,12 @@ void kernel_init(void)
 
     thread_create(idle_stack, sizeof(idle_stack),
             THREAD_PRIORITY_IDLE,
-            CREATE_WOUT_YIELD | CREATE_STACKTEST,
+            THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
             idle_thread, NULL, idle_name);
 
     thread_create(main_stack, sizeof(main_stack),
             THREAD_PRIORITY_MAIN,
-            CREATE_WOUT_YIELD | CREATE_STACKTEST,
+            THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
             main_trampoline, NULL, main_name);
 
     cpu_switch_context_exit();
diff --git a/core/msg.c b/core/msg.c
index 8d2262063e..45999420b7 100644
--- a/core/msg.c
+++ b/core/msg.c
@@ -31,8 +31,6 @@
 #include "irq.h"
 #include "cib.h"
 
-#include "flags.h"
-
 #define ENABLE_DEBUG    (0)
 #include "debug.h"
 #include "thread.h"
diff --git a/core/thread.c b/core/thread.c
index 2af644b603..1180cbbb2d 100644
--- a/core/thread.c
+++ b/core/thread.c
@@ -148,7 +148,7 @@ kernel_pid_t thread_create(char *stack, int stacksize, char priority, int flags,
     tcb_t *cb = (tcb_t *) (stack + stacksize);
 
 #if defined(DEVELHELP) || defined(SCHED_TEST_STACK)
-    if (flags & CREATE_STACKTEST) {
+    if (flags & THREAD_CREATE_STACKTEST) {
         /* assign each int of the stack the value of it's address */
         uintptr_t *stackmax = (uintptr_t *) (stack + stacksize);
         uintptr_t *stackp = (uintptr_t *) stack;
@@ -212,13 +212,13 @@ kernel_pid_t thread_create(char *stack, int stacksize, char priority, int flags,
 
     DEBUG("Created thread %s. PID: %" PRIkernel_pid ". Priority: %u.\n", name, cb->pid, priority);
 
-    if (flags & CREATE_SLEEPING) {
+    if (flags & THREAD_CREATE_SLEEPING) {
         sched_set_status(cb, STATUS_SLEEPING);
     }
     else {
         sched_set_status(cb, STATUS_PENDING);
 
-        if (!(flags & CREATE_WOUT_YIELD)) {
+        if (!(flags & THREAD_CREATE_WOUT_YIELD)) {
             restoreIRQ(state);
             sched_switch(priority);
             return pid;
diff --git a/examples/gnrc_tftp/tftp_server.c b/examples/gnrc_tftp/tftp_server.c
index b825b0831d..7dabab8496 100644
--- a/examples/gnrc_tftp/tftp_server.c
+++ b/examples/gnrc_tftp/tftp_server.c
@@ -156,7 +156,7 @@ void *tftp_server_wrapper(void *arg)
 void tftp_server_start(void)
 {
     thread_create(_tftp_stack, sizeof(_tftp_stack),
-                  1, CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                  1, THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                   tftp_server_wrapper, NULL, "TFTP Server");
 }
 
diff --git a/examples/ipc_pingpong/main.c b/examples/ipc_pingpong/main.c
index f3fd69daf9..655ff39a74 100644
--- a/examples/ipc_pingpong/main.c
+++ b/examples/ipc_pingpong/main.c
@@ -51,7 +51,7 @@ int main(void)
     msg_t m;
 
     kernel_pid_t pid = thread_create(second_thread_stack, sizeof(second_thread_stack),
-                            THREAD_PRIORITY_MAIN - 1, CREATE_STACKTEST,
+                            THREAD_PRIORITY_MAIN - 1, THREAD_CREATE_STACKTEST,
                             second_thread, NULL, "pong");
 
     m.content.value = 1;
diff --git a/examples/posix_sockets/udp.c b/examples/posix_sockets/udp.c
index d29d560e84..c386c1e275 100644
--- a/examples/posix_sockets/udp.c
+++ b/examples/posix_sockets/udp.c
@@ -130,7 +130,8 @@ static int udp_start_server(char *port_str)
     }
     /* start server (which means registering pktdump for the chosen port) */
     if (thread_create(server_stack, sizeof(server_stack), THREAD_PRIORITY_MAIN - 1,
-                      CREATE_STACKTEST, _server_thread, port_str, "UDP server") <= KERNEL_PID_UNDEF) {
+                      THREAD_CREATE_STACKTEST,
+                      _server_thread, port_str, "UDP server") <= KERNEL_PID_UNDEF) {
         server_socket = -1;
         puts("error initializing thread");
         return 1;
diff --git a/examples/riot_and_cpp/main.cpp b/examples/riot_and_cpp/main.cpp
index 4429c4690b..b53a356bb4 100644
--- a/examples/riot_and_cpp/main.cpp
+++ b/examples/riot_and_cpp/main.cpp
@@ -49,7 +49,9 @@ int main()
     printf("\n");
 
     /* create thread A */
-    thread_create(threadA_stack, sizeof(threadA_stack), 0, CREATE_WOUT_YIELD, threadA_func, NULL, "thread A");
+    thread_create(threadA_stack, sizeof(threadA_stack), 0,
+                                        THREAD_CREATE_WOUT_YIELD,
+                                        threadA_func, NULL, "thread A");
 
     printf("******** Hello, you're in thread #%" PRIkernel_pid " ********\n", sched_active_pid);
     printf("We'll test C++ class and methods here!\n");
diff --git a/sys/cpp11-compat/include/riot/thread.hpp b/sys/cpp11-compat/include/riot/thread.hpp
index 734a1750aa..a18e580ced 100644
--- a/sys/cpp11-compat/include/riot/thread.hpp
+++ b/sys/cpp11-compat/include/riot/thread.hpp
@@ -228,7 +228,7 @@ thread::thread(F&& f, Args&&... args)
   std::unique_ptr<func_and_args> p(
     new func_and_args(m_data.get(), forward<F>(f), forward<Args>(args)...));
   m_handle = thread_create(
-    m_data->stack, stack_size, THREAD_PRIORITY_MAIN - 1, 0, // CREATE_WOUT_YIELD
+    m_data->stack, stack_size, THREAD_PRIORITY_MAIN - 1, 0,
     &thread_proxy<func_and_args>, p.get(), "riot_cpp_thread");
   if (m_handle >= 0) {
     p.release();
diff --git a/sys/net/gnrc/application_layer/zep/gnrc_zep.c b/sys/net/gnrc/application_layer/zep/gnrc_zep.c
index 7248d7e967..24b042f5a2 100644
--- a/sys/net/gnrc/application_layer/zep/gnrc_zep.c
+++ b/sys/net/gnrc/application_layer/zep/gnrc_zep.c
@@ -163,7 +163,7 @@ kernel_pid_t gnrc_zep_init(gnrc_zep_t *dev, uint16_t src_port, ipv6_addr_t *dst,
     dev->lqi_mode = 1;
 
     _pid = thread_create(_rx_stack, GNRC_ZEP_STACK_SIZE, GNRC_ZEP_PRIO,
-                         CREATE_STACKTEST, _event_loop, dev, "zep_app");
+                         THREAD_CREATE_STACKTEST, _event_loop, dev, "zep_app");
 
     DEBUG("zep: started thread with PID %" PRIkernel_pid "\n", _pid);
 
diff --git a/sys/net/gnrc/link_layer/netdev2/gnrc_netdev2.c b/sys/net/gnrc/link_layer/netdev2/gnrc_netdev2.c
index e618c4a40f..278f4044e7 100644
--- a/sys/net/gnrc/link_layer/netdev2/gnrc_netdev2.c
+++ b/sys/net/gnrc/link_layer/netdev2/gnrc_netdev2.c
@@ -186,7 +186,7 @@ kernel_pid_t gnrc_netdev2_init(char *stack, int stacksize, char priority,
     }
 
     /* create new gnrc_netdev2 thread */
-    res = thread_create(stack, stacksize, priority, CREATE_STACKTEST,
+    res = thread_create(stack, stacksize, priority, THREAD_CREATE_STACKTEST,
                          _gnrc_netdev2_thread, (void *)gnrc_netdev2, name);
     if (res <= 0) {
         return -EINVAL;
diff --git a/sys/net/gnrc/link_layer/nomac/gnrc_nomac.c b/sys/net/gnrc/link_layer/nomac/gnrc_nomac.c
index fb64ee9b18..101549a867 100644
--- a/sys/net/gnrc/link_layer/nomac/gnrc_nomac.c
+++ b/sys/net/gnrc/link_layer/nomac/gnrc_nomac.c
@@ -138,7 +138,7 @@ kernel_pid_t gnrc_nomac_init(char *stack, int stacksize, char priority,
         return -ENODEV;
     }
     /* create new NOMAC thread */
-    res = thread_create(stack, stacksize, priority, CREATE_STACKTEST,
+    res = thread_create(stack, stacksize, priority, THREAD_CREATE_STACKTEST,
                         _nomac_thread, (void *)dev, name);
     if (res <= 0) {
         return -EINVAL;
diff --git a/sys/net/gnrc/link_layer/slip/gnrc_slip.c b/sys/net/gnrc/link_layer/slip/gnrc_slip.c
index 810c587a6d..3664793660 100644
--- a/sys/net/gnrc/link_layer/slip/gnrc_slip.c
+++ b/sys/net/gnrc/link_layer/slip/gnrc_slip.c
@@ -268,7 +268,7 @@ kernel_pid_t gnrc_slip_init(gnrc_slip_dev_t *dev, uart_t uart, uint32_t baudrate
 
     /* start SLIP thread */
     DEBUG("slip: starting SLIP thread\n");
-    pid = thread_create(stack, stack_size, priority, CREATE_STACKTEST,
+    pid = thread_create(stack, stack_size, priority, THREAD_CREATE_STACKTEST,
                         _slip, dev, _SLIP_NAME);
     if (pid < 0) {
         DEBUG("slip: unable to create SLIP thread\n");
diff --git a/sys/net/gnrc/nettest/gnrc_nettest.c b/sys/net/gnrc/nettest/gnrc_nettest.c
index d5d07a3b23..5259935efc 100644
--- a/sys/net/gnrc/nettest/gnrc_nettest.c
+++ b/sys/net/gnrc/nettest/gnrc_nettest.c
@@ -187,7 +187,8 @@ int gnrc_nettest_init(void)
 {
     if (_pid <= KERNEL_PID_UNDEF) {
         _pid = thread_create(_stack, sizeof(_stack), GNRC_NETTEST_PRIO,
-                             CREATE_STACKTEST, _event_loop, NULL, "nettest");
+                             THREAD_CREATE_STACKTEST,
+                             _event_loop, NULL, "nettest");
     }
 
     return _pid;
diff --git a/sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c b/sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c
index 114bafd485..44a3a10626 100644
--- a/sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c
+++ b/sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c
@@ -85,7 +85,8 @@ kernel_pid_t gnrc_ipv6_init(void)
 {
     if (gnrc_ipv6_pid == KERNEL_PID_UNDEF) {
         gnrc_ipv6_pid = thread_create(_stack, sizeof(_stack), GNRC_IPV6_PRIO,
-                                      CREATE_STACKTEST, _event_loop, NULL, "ipv6");
+                                      THREAD_CREATE_STACKTEST,
+                                      _event_loop, NULL, "ipv6");
     }
 
 #ifdef MODULE_FIB
diff --git a/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c b/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
index caee0895a9..648d62e78f 100644
--- a/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
+++ b/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
@@ -55,7 +55,7 @@ kernel_pid_t gnrc_sixlowpan_init(void)
     }
 
     _pid = thread_create(_stack, sizeof(_stack), GNRC_SIXLOWPAN_PRIO,
-                         CREATE_STACKTEST, _event_loop, NULL, "6lo");
+                         THREAD_CREATE_STACKTEST, _event_loop, NULL, "6lo");
 
     return _pid;
 }
diff --git a/sys/net/gnrc/pktdump/gnrc_pktdump.c b/sys/net/gnrc/pktdump/gnrc_pktdump.c
index 88abca944f..a454791b96 100644
--- a/sys/net/gnrc/pktdump/gnrc_pktdump.c
+++ b/sys/net/gnrc/pktdump/gnrc_pktdump.c
@@ -164,7 +164,8 @@ kernel_pid_t gnrc_pktdump_init(void)
 {
     if (_pid == KERNEL_PID_UNDEF) {
         _pid = thread_create(_stack, sizeof(_stack), GNRC_PKTDUMP_PRIO,
-                             CREATE_STACKTEST, _eventloop, NULL, "pktdump");
+                             THREAD_CREATE_STACKTEST,
+                             _eventloop, NULL, "pktdump");
     }
     return _pid;
 }
diff --git a/sys/net/gnrc/routing/rpl/gnrc_rpl.c b/sys/net/gnrc/routing/rpl/gnrc_rpl.c
index 2745bc89b7..beeba45103 100644
--- a/sys/net/gnrc/routing/rpl/gnrc_rpl.c
+++ b/sys/net/gnrc/routing/rpl/gnrc_rpl.c
@@ -49,8 +49,9 @@ kernel_pid_t gnrc_rpl_init(kernel_pid_t if_pid)
     if (gnrc_rpl_pid == KERNEL_PID_UNDEF) {
         _instance_id = 0;
         /* start the event loop */
-        gnrc_rpl_pid = thread_create(_stack, sizeof(_stack), GNRC_RPL_PRIO, CREATE_STACKTEST,
-                _event_loop, NULL, "RPL");
+        gnrc_rpl_pid = thread_create(_stack, sizeof(_stack), GNRC_RPL_PRIO,
+                                     THREAD_CREATE_STACKTEST,
+                                     _event_loop, NULL, "RPL");
 
         if (gnrc_rpl_pid == KERNEL_PID_UNDEF) {
             DEBUG("RPL: could not start the event loop\n");
diff --git a/sys/net/gnrc/transport_layer/udp/gnrc_udp.c b/sys/net/gnrc/transport_layer/udp/gnrc_udp.c
index 28034a5380..f6d33bf154 100644
--- a/sys/net/gnrc/transport_layer/udp/gnrc_udp.c
+++ b/sys/net/gnrc/transport_layer/udp/gnrc_udp.c
@@ -277,7 +277,7 @@ int gnrc_udp_init(void)
     if (_pid == KERNEL_PID_UNDEF) {
         /* start UDP thread */
         _pid = thread_create(_stack, sizeof(_stack), GNRC_UDP_PRIO,
-                             CREATE_STACKTEST, _event_loop, NULL, "udp");
+                             THREAD_CREATE_STACKTEST, _event_loop, NULL, "udp");
     }
     return _pid;
 }
diff --git a/sys/net/routing/nhdp/nhdp.c b/sys/net/routing/nhdp/nhdp.c
index 82e96d2c9f..b5f00aec77 100644
--- a/sys/net/routing/nhdp/nhdp.c
+++ b/sys/net/routing/nhdp/nhdp.c
@@ -94,7 +94,7 @@ kernel_pid_t nhdp_start(void)
 
         /* Start the NHDP thread */
         nhdp_pid = thread_create(nhdp_stack, sizeof(nhdp_stack), THREAD_PRIORITY_MAIN - 1,
-                                 CREATE_STACKTEST, _nhdp_runner, NULL, "NHDP");
+                                 THREAD_CREATE_STACKTEST, _nhdp_runner, NULL, "NHDP");
 
 #if (NHDP_METRIC_NEEDS_TIMER)
         /* Configure periodic timer message to refresh metric values */
@@ -193,7 +193,7 @@ int nhdp_register_if(kernel_pid_t if_pid, uint8_t *addr, size_t addr_size, uint8
 
     /* Start the receiving thread */
     nhdp_rcv_pid = thread_create(nhdp_rcv_stack, sizeof(nhdp_rcv_stack), THREAD_PRIORITY_MAIN - 1,
-                                 CREATE_STACKTEST, _nhdp_receiver, NULL, "nhdp_rcv_thread");
+                                 THREAD_CREATE_STACKTEST, _nhdp_receiver, NULL, "nhdp_rcv_thread");
 
     /* Start sending periodic HELLO */
     signal_msg.type = MSG_TIMER;
diff --git a/sys/posix/pthread/pthread.c b/sys/posix/pthread/pthread.c
index 26b01ac923..2d72161245 100644
--- a/sys/posix/pthread/pthread.c
+++ b/sys/posix/pthread/pthread.c
@@ -143,7 +143,7 @@ int pthread_create(pthread_t *newthread, const pthread_attr_t *attr, void *(*sta
             volatile kernel_pid_t pid = thread_create(pthread_reaper_stack,
                                              PTHREAD_REAPER_STACKSIZE,
                                              0,
-                                             CREATE_STACKTEST,
+                                             THREAD_CREATE_STACKTEST,
                                              pthread_reaper,
                                              NULL,
                                              "pthread-reaper");
@@ -155,7 +155,8 @@ int pthread_create(pthread_t *newthread, const pthread_attr_t *attr, void *(*sta
     pt->thread_pid = thread_create(stack,
                                    stack_size,
                                    THREAD_PRIORITY_MAIN,
-                                   CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                                   THREAD_CREATE_WOUT_YIELD |
+                                   THREAD_CREATE_STACKTEST,
                                    pthread_start_routine,
                                    pt,
                                    "pthread");
diff --git a/tests/conn_ip/ip.c b/tests/conn_ip/ip.c
index fcbed6b91e..03614ba94f 100644
--- a/tests/conn_ip/ip.c
+++ b/tests/conn_ip/ip.c
@@ -147,7 +147,7 @@ static int ip_send(char *addr_str, char *port_str, char *data, unsigned int num,
 static int ip_start_server(char *port_str)
 {
     if (thread_create(server_stack, sizeof(server_stack), THREAD_PRIORITY_MAIN - 1,
-                      CREATE_STACKTEST, _server_thread, port_str, "IP server") <= KERNEL_PID_UNDEF) {
+                      THREAD_CREATE_STACKTEST, _server_thread, port_str, "IP server") <= KERNEL_PID_UNDEF) {
         return 1;
     }
     return 0;
diff --git a/tests/driver_pir/main.c b/tests/driver_pir/main.c
index 6ebae50437..91323907a8 100644
--- a/tests/driver_pir/main.c
+++ b/tests/driver_pir/main.c
@@ -80,7 +80,7 @@ int main(void)
 #else
    thread_create(
            pir_handler_stack, sizeof(pir_handler_stack), THREAD_PRIORITY_MAIN - 1,
-           CREATE_WOUT_YIELD | CREATE_STACKTEST,
+           THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
            pir_handler, NULL, "pir_handler");
 #endif
     return 0;
diff --git a/tests/irq/main.c b/tests/irq/main.c
index 940e3e2fef..dcf1e77179 100644
--- a/tests/irq/main.c
+++ b/tests/irq/main.c
@@ -54,7 +54,7 @@ int main(void)
     busy = 1;
     k = 23;
     thread_create(busy_stack, sizeof(busy_stack),
-                  THREAD_PRIORITY_MAIN + 1, CREATE_WOUT_YIELD,
+                  THREAD_PRIORITY_MAIN + 1, THREAD_CREATE_WOUT_YIELD,
                   busy_thread, NULL, "busy_thread");
     puts("busy_thread created");
 
diff --git a/tests/mutex_unlock_and_sleep/main.c b/tests/mutex_unlock_and_sleep/main.c
index 95ff54bc1a..96389b2cd7 100644
--- a/tests/mutex_unlock_and_sleep/main.c
+++ b/tests/mutex_unlock_and_sleep/main.c
@@ -49,7 +49,7 @@ int main(void)
     kernel_pid_t second_pid = thread_create(stack,
                   sizeof(stack),
                   THREAD_PRIORITY_MAIN - 1,
-                  CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                  THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                   second_thread,
                   NULL,
                   "second_thread");
diff --git a/tests/pipe/main.c b/tests/pipe/main.c
index f1edc2a20d..41805a305e 100644
--- a/tests/pipe/main.c
+++ b/tests/pipe/main.c
@@ -29,7 +29,6 @@
 #include <inttypes.h>
 
 #include "thread.h"
-#include "flags.h"
 #include "kernel.h"
 #include "pipe.h"
 #include "pipe.h"
@@ -101,10 +100,12 @@ int main(void)
     }
 
     thread_create(stacks[0], sizeof (stacks[0]),
-                  THREAD_PRIORITY_MAIN, CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                  THREAD_PRIORITY_MAIN,
+                  THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                   run_middle, NULL, "middle");
     thread_create(stacks[1], sizeof (stacks[1]),
-                  THREAD_PRIORITY_MAIN, CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                  THREAD_PRIORITY_MAIN,
+                  THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                   run_end, NULL, "end");
 
     unsigned total = 0;
diff --git a/tests/posix_semaphore/main.c b/tests/posix_semaphore/main.c
index 155696fbf2..7330f2654b 100644
--- a/tests/posix_semaphore/main.c
+++ b/tests/posix_semaphore/main.c
@@ -77,7 +77,8 @@ static void test1(void)
     kernel_pid_t pid = thread_create(test1_thread_stack,
                                      sizeof(test1_thread_stack),
                                      THREAD_PRIORITY_MAIN - 1,
-                                     CREATE_STACKTEST | CREATE_WOUT_YIELD,
+                                     THREAD_CREATE_STACKTEST |
+                                     THREAD_CREATE_WOUT_YIELD,
                                      test1_second_thread,
                                      NULL,
                                      "second");
@@ -154,7 +155,7 @@ void test2(void)
         kernel_pid_t pid = thread_create(test2_thread_stack[i],
                                          sizeof(test2_thread_stack[i]),
                                          priority,
-                                         CREATE_STACKTEST,
+                                         THREAD_CREATE_STACKTEST,
                                          priority_sema_thread,
                                          names[i],
                                          names[i]);
@@ -211,14 +212,14 @@ void test3(void)
     }
     puts("first: create thread 1");
     if (thread_create(test2_thread_stack[0], sizeof(test2_thread_stack[0]),
-                      THREAD_PRIORITY_MAIN - 1, CREATE_STACKTEST,
+                      THREAD_PRIORITY_MAIN - 1, THREAD_CREATE_STACKTEST,
                       test3_one_two_thread, NULL, "thread 1") < 0) {
         puts("first: thread create FAILED");
         return;
     }
     puts("first: create thread 2");
     if (thread_create(test2_thread_stack[1], sizeof(test2_thread_stack[1]),
-                      THREAD_PRIORITY_MAIN - 1, CREATE_STACKTEST,
+                      THREAD_PRIORITY_MAIN - 1, THREAD_CREATE_STACKTEST,
                       test3_two_one_thread, NULL, "thread 2") < 0) {
         puts("first: thread create FAILED");
         return;
diff --git a/tests/pthread_condition_variable/main.c b/tests/pthread_condition_variable/main.c
index 630d077472..cee1143b94 100644
--- a/tests/pthread_condition_variable/main.c
+++ b/tests/pthread_condition_variable/main.c
@@ -58,7 +58,7 @@ int main(void)
     pthread_cond_init(&cv, NULL);
 
     kernel_pid_t pid = thread_create(stack,sizeof(stack), THREAD_PRIORITY_MAIN - 1,
-                                     CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                                     THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                                      second_thread, NULL, "second_thread");
 
     while (1) {
diff --git a/tests/pthread_rwlock/main.c b/tests/pthread_rwlock/main.c
index b91f4d1b2a..f8b603fbfa 100644
--- a/tests/pthread_rwlock/main.c
+++ b/tests/pthread_rwlock/main.c
@@ -128,7 +128,7 @@ int main(void)
         }
 
         thread_create(stacks[i], sizeof(stacks[i]),
-                      prio, CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                      prio, THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                       fun, NULL, name);
     }
 
diff --git a/tests/sched_testing/main.c b/tests/sched_testing/main.c
index 3b8edf64c6..3e8a575002 100644
--- a/tests/sched_testing/main.c
+++ b/tests/sched_testing/main.c
@@ -34,7 +34,7 @@ int main(void)
     puts("----------------------------------------------------------------");
 
     thread_create(snd_thread_stack, sizeof(snd_thread_stack), THREAD_PRIORITY_MAIN,
-                  CREATE_WOUT_YIELD, snd_thread, NULL, "snd");
+                  THREAD_CREATE_WOUT_YIELD, snd_thread, NULL, "snd");
 
     puts("yield 1");
     thread_yield();
diff --git a/tests/thread_basic/main.c b/tests/thread_basic/main.c
index a8fb8e3a72..457668095a 100644
--- a/tests/thread_basic/main.c
+++ b/tests/thread_basic/main.c
@@ -34,7 +34,8 @@ int main(void)
 {
     (void) thread_create(
             t2_stack, sizeof(t2_stack),
-            THREAD_PRIORITY_MAIN - 1, CREATE_WOUT_YIELD | CREATE_STACKTEST,
+            THREAD_PRIORITY_MAIN - 1,
+            THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
             second_thread, NULL, "nr2");
     puts("first thread\n");
     return 0;
diff --git a/tests/thread_cooperation/main.c b/tests/thread_cooperation/main.c
index 6ef2291c2a..41b2e16d66 100644
--- a/tests/thread_cooperation/main.c
+++ b/tests/thread_cooperation/main.c
@@ -70,7 +70,8 @@ int main(void)
     for (int i = 0; i < PROBLEM; ++i) {
         printf("Creating thread with arg %d\n", (i + 1));
         ths[i] = thread_create(stacks[i], sizeof(stacks[i]),
-                               THREAD_PRIORITY_MAIN - 1, CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                               THREAD_PRIORITY_MAIN - 1,
+                               THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                                run, NULL, "thread");
 
         if (ths[i] < 0)  {
diff --git a/tests/thread_exit/main.c b/tests/thread_exit/main.c
index 6d214b10c3..10b4d56a8b 100644
--- a/tests/thread_exit/main.c
+++ b/tests/thread_exit/main.c
@@ -50,7 +50,7 @@ void *second_thread(void *arg)
              third_thread_stack,
              sizeof(third_thread_stack),
              THREAD_PRIORITY_MAIN - 2,
-             CREATE_STACKTEST,
+             THREAD_CREATE_STACKTEST,
              third_thread,
              NULL,
              "nr3")
@@ -64,7 +64,7 @@ void *second_thread(void *arg)
              third_thread_stack,
              sizeof(third_thread_stack),
              THREAD_PRIORITY_MAIN - 1,
-             CREATE_WOUT_YIELD | CREATE_STACKTEST,
+             THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
              fourth_thread,
              NULL,
              "nr4")
@@ -84,7 +84,7 @@ int main(void)
              second_thread_stack,
              sizeof(second_thread_stack),
              THREAD_PRIORITY_MAIN - 1,
-             CREATE_WOUT_YIELD | CREATE_STACKTEST,
+             THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
              second_thread,
              NULL,
              "nr2")
diff --git a/tests/thread_msg/main.c b/tests/thread_msg/main.c
index 6b85f2e638..dcd21699c2 100644
--- a/tests/thread_msg/main.c
+++ b/tests/thread_msg/main.c
@@ -84,13 +84,13 @@ void *thread3(void *arg)
 int main(void)
 {
     p1 = thread_create(t1_stack, sizeof(t1_stack), THREAD_PRIORITY_MAIN - 1,
-                       CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                       THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                        thread1, NULL, "nr1");
     p2 = thread_create(t2_stack, sizeof(t2_stack), THREAD_PRIORITY_MAIN - 1,
-                       CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                       THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                        thread2, NULL, "nr2");
     p3 = thread_create(t3_stack, sizeof(t3_stack), THREAD_PRIORITY_MAIN - 1,
-                       CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                       THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                        thread3, NULL, "nr3");
     puts("THREADS CREATED\n");
     return 0;
diff --git a/tests/thread_msg_block_w_queue/main.c b/tests/thread_msg_block_w_queue/main.c
index f9a9545a3e..549d12e688 100644
--- a/tests/thread_msg_block_w_queue/main.c
+++ b/tests/thread_msg_block_w_queue/main.c
@@ -60,7 +60,7 @@ int main(void)
     msg_init_queue(msg_q, 1);
 
     p1 = thread_create(t1_stack, sizeof(t1_stack), THREAD_PRIORITY_MAIN - 1,
-                       CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                       THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                        thread1, NULL, "nr1");
 
     /* step 3: receive a msg */
diff --git a/tests/thread_msg_block_wo_queue/main.c b/tests/thread_msg_block_wo_queue/main.c
index 0b0aed9e46..cce12b5ea2 100644
--- a/tests/thread_msg_block_wo_queue/main.c
+++ b/tests/thread_msg_block_wo_queue/main.c
@@ -57,7 +57,7 @@ int main(void)
     p_main = sched_active_pid;
 
     p1 = thread_create(t1_stack, sizeof(t1_stack), THREAD_PRIORITY_MAIN - 1,
-                       CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                       THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                        thread1, NULL, "nr1");
 
     /* step 3: receive a msg */
diff --git a/tests/thread_msg_seq/main.c b/tests/thread_msg_seq/main.c
index 4e430135c5..f07b81264b 100644
--- a/tests/thread_msg_seq/main.c
+++ b/tests/thread_msg_seq/main.c
@@ -56,13 +56,13 @@ int main(void)
     p_main = sched_active_pid;
 
     p1 = thread_create(t1_stack, sizeof(t1_stack), THREAD_PRIORITY_MAIN - 1,
-                       CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                       THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                        sub_thread, "nr1", "nr1");
     p2 = thread_create(t2_stack, sizeof(t2_stack), THREAD_PRIORITY_MAIN - 1,
-                       CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                       THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                        sub_thread, "nr2", "nr2");
     p3 = thread_create(t3_stack, sizeof(t3_stack), THREAD_PRIORITY_MAIN - 1,
-                       CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                       THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
                        sub_thread, "nr3", "nr3");
 
     puts("THREADS CREATED\n");
diff --git a/tests/unittests/tests-core/tests-core-ringbuffer.c b/tests/unittests/tests-core/tests-core-ringbuffer.c
index 694aa20157..f4b3525bed 100644
--- a/tests/unittests/tests-core/tests-core-ringbuffer.c
+++ b/tests/unittests/tests-core/tests-core-ringbuffer.c
@@ -17,7 +17,6 @@
  */
 
 #include "thread.h"
-#include "flags.h"
 #include "kernel.h"
 #include "ringbuffer.h"
 #include "mutex.h"
@@ -110,7 +109,8 @@ static void tests_core_ringbuffer(void)
 {
     pid_add = sched_active_pid;
     pid_get = thread_create(stack_get, sizeof (stack_get),
-                            THREAD_PRIORITY_MAIN, CREATE_SLEEPING | CREATE_STACKTEST,
+                            THREAD_PRIORITY_MAIN,
+                            THREAD_CREATE_SLEEPING | THREAD_CREATE_STACKTEST,
                             run_get, NULL, "get");
     run_add();
 }
diff --git a/tests/unittests/tests-ubjson/tests-ubjson.c b/tests/unittests/tests-ubjson/tests-ubjson.c
index f20361f4c5..984c9c522c 100644
--- a/tests/unittests/tests-ubjson/tests-ubjson.c
+++ b/tests/unittests/tests-ubjson/tests-ubjson.c
@@ -87,7 +87,8 @@ void test_ubjson_test(void (*sender_fun)(void), void (*receiver_fun)(void))
     mutex_lock(&data.mutexes[1]);
 
     kernel_pid_t receiver_pid = thread_create(receiver_stack, sizeof(receiver_stack),
-                                              THREAD_PRIORITY_MAIN, CREATE_WOUT_YIELD,
+                                              THREAD_PRIORITY_MAIN,
+                                              THREAD_CREATE_WOUT_YIELD,
                                               test_ubjson_receiver_trampoline, &data, "receiver");
     TEST_ASSERT(pid_is_valid(receiver_pid));
 
diff --git a/tests/vtimer_msg/main.c b/tests/vtimer_msg/main.c
index 5af1324774..1199e2b509 100644
--- a/tests/vtimer_msg/main.c
+++ b/tests/vtimer_msg/main.c
@@ -94,7 +94,7 @@ int main(void)
                   timer_stack,
                   sizeof(timer_stack),
                   THREAD_PRIORITY_MAIN - 1,
-                  CREATE_STACKTEST,
+                  THREAD_CREATE_STACKTEST,
                   timer_thread,
                   NULL,
                   "timer");
@@ -111,7 +111,7 @@ int main(void)
                    timer_stack_local,
                    sizeof(timer_stack_local),
                    THREAD_PRIORITY_MAIN - 1,
-                   CREATE_STACKTEST,
+                   THREAD_CREATE_STACKTEST,
                    timer_thread_local,
                    NULL,
                    "timer local");
diff --git a/tests/vtimer_msg_diff/main.c b/tests/vtimer_msg_diff/main.c
index 0cd42d6d07..3723be63cc 100644
--- a/tests/vtimer_msg_diff/main.c
+++ b/tests/vtimer_msg_diff/main.c
@@ -108,7 +108,7 @@ int main(void)
                   timer_stack,
                   sizeof(timer_stack),
                   THREAD_PRIORITY_MAIN - 1,
-                  CREATE_STACKTEST,
+                  THREAD_CREATE_STACKTEST,
                   timer_thread,
                   NULL,
                   "timer");
diff --git a/tests/xtimer_drift/main.c b/tests/xtimer_drift/main.c
index 1ed51ca6ab..32840754f1 100644
--- a/tests/xtimer_drift/main.c
+++ b/tests/xtimer_drift/main.c
@@ -140,7 +140,7 @@ int main(void)
         slacker_stack1,
         sizeof(slacker_stack1),
         THREAD_PRIORITY_MAIN - 1,
-        CREATE_STACKTEST,
+        THREAD_CREATE_STACKTEST,
         slacker_thread,
         NULL,
         "slacker1");
@@ -157,7 +157,7 @@ int main(void)
         slacker_stack2,
         sizeof(slacker_stack2),
         THREAD_PRIORITY_MAIN - 1,
-        CREATE_STACKTEST,
+        THREAD_CREATE_STACKTEST,
         slacker_thread,
         NULL,
         "slacker2");
@@ -174,7 +174,7 @@ int main(void)
                    worker_stack,
                    sizeof(worker_stack),
                    THREAD_PRIORITY_MAIN - 1,
-                   CREATE_STACKTEST,
+                   THREAD_CREATE_STACKTEST,
                    worker_thread,
                    NULL,
                    "worker");
diff --git a/tests/xtimer_hang/main.c b/tests/xtimer_hang/main.c
index 4118c36156..8faaf50c65 100644
--- a/tests/xtimer_hang/main.c
+++ b/tests/xtimer_hang/main.c
@@ -64,7 +64,7 @@ int main(void)
     thread_create(stack_timer1,
                   STACKSIZE_TIMER,
                   2,
-                  CREATE_STACKTEST,
+                  THREAD_CREATE_STACKTEST,
                   timer_func1,
                   NULL,
                   "timer1");
@@ -72,7 +72,7 @@ int main(void)
     thread_create(stack_timer2,
                   STACKSIZE_TIMER,
                   3,
-                  CREATE_STACKTEST,
+                  THREAD_CREATE_STACKTEST,
                   timer_func2,
                   NULL,
                   "timer2");
diff --git a/tests/xtimer_msg/main.c b/tests/xtimer_msg/main.c
index 3ed46da299..341da6119b 100644
--- a/tests/xtimer_msg/main.c
+++ b/tests/xtimer_msg/main.c
@@ -98,7 +98,7 @@ int main(void)
                   timer_stack,
                   sizeof(timer_stack),
                   THREAD_PRIORITY_MAIN - 1,
-                  CREATE_STACKTEST,
+                  THREAD_CREATE_STACKTEST,
                   timer_thread,
                   NULL,
                   "timer");
@@ -115,7 +115,7 @@ int main(void)
                    timer_stack_local,
                    sizeof(timer_stack_local),
                    THREAD_PRIORITY_MAIN - 1,
-                   CREATE_STACKTEST,
+                   THREAD_CREATE_STACKTEST,
                    timer_thread_local,
                    NULL,
                    "timer local");