diff --git a/sys/auto_init/usb/auto_init_usb.c b/sys/auto_init/usb/auto_init_usb.c
index dfcabbd5d3..176aa8819c 100644
--- a/sys/auto_init/usb/auto_init_usb.c
+++ b/sys/auto_init/usb/auto_init_usb.c
@@ -24,6 +24,8 @@
 
 #define USB_H_USER_IS_RIOT_INTERNAL
 
+#include <assert.h>
+
 #include "usb/usbus.h"
 
 #ifdef MODULE_USBUS_CDC_ECM
diff --git a/sys/can/conn/isotp.c b/sys/can/conn/isotp.c
index 119d99ebed..3bc202f7d6 100644
--- a/sys/can/conn/isotp.c
+++ b/sys/can/conn/isotp.c
@@ -17,6 +17,7 @@
  */
 
 #ifdef MODULE_CAN_ISOTP
+#include <assert.h>
 #include <errno.h>
 #include <string.h>
 
diff --git a/sys/can/conn/raw.c b/sys/can/conn/raw.c
index 64ec1d5257..08c6ea3ee2 100644
--- a/sys/can/conn/raw.c
+++ b/sys/can/conn/raw.c
@@ -16,6 +16,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <string.h>
 
diff --git a/sys/can/device.c b/sys/can/device.c
index a366d88327..07afd9a40f 100644
--- a/sys/can/device.c
+++ b/sys/can/device.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 
 #include "thread.h"
diff --git a/sys/can/dll.c b/sys/can/dll.c
index adf9dfb4e4..f918208e0b 100644
--- a/sys/can/dll.c
+++ b/sys/can/dll.c
@@ -23,6 +23,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <string.h>
 
diff --git a/sys/can/isotp/isotp.c b/sys/can/isotp/isotp.c
index 5d667c765b..dfc6a4f305 100644
--- a/sys/can/isotp/isotp.c
+++ b/sys/can/isotp/isotp.c
@@ -16,6 +16,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <string.h>
 
diff --git a/sys/can/pkt.c b/sys/can/pkt.c
index 32faa7d4db..14747d7d70 100644
--- a/sys/can/pkt.c
+++ b/sys/can/pkt.c
@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <string.h>
 #include <limits.h>
 #include <errno.h>
diff --git a/sys/crypto/modes/ccm.c b/sys/crypto/modes/ccm.c
index c76088dc1b..82b3468ec6 100644
--- a/sys/crypto/modes/ccm.c
+++ b/sys/crypto/modes/ccm.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <string.h>
 #include "debug.h"
 #include "crypto/helper.h"
diff --git a/sys/fuzzing/netdev.c b/sys/fuzzing/netdev.c
index a079e6698d..cb0d07f05a 100644
--- a/sys/fuzzing/netdev.c
+++ b/sys/fuzzing/netdev.c
@@ -6,6 +6,7 @@
  * directory for more details.
  */
 
+#include <assert.h>
 #include <stddef.h>
 
 #include "mutex.h"
diff --git a/sys/irq_handler/irq_handler.c b/sys/irq_handler/irq_handler.c
index f4859a2acc..e901061f4d 100644
--- a/sys/irq_handler/irq_handler.c
+++ b/sys/irq_handler/irq_handler.c
@@ -6,6 +6,7 @@
  * directory for more details.
  */
 
+#include <assert.h>
 #include <inttypes.h>
 #include <errno.h>
 
diff --git a/sys/memarray/memarray.c b/sys/memarray/memarray.c
index c046697584..f12c1856d6 100644
--- a/sys/memarray/memarray.c
+++ b/sys/memarray/memarray.c
@@ -6,6 +6,7 @@
  * directory for more details.
  */
 
+#include <assert.h>
 #include <string.h>
 #include "memarray.h"
 
diff --git a/sys/net/application_layer/asymcute/asymcute.c b/sys/net/application_layer/asymcute/asymcute.c
index 9cbbe39fd5..e53097c5c1 100644
--- a/sys/net/application_layer/asymcute/asymcute.c
+++ b/sys/net/application_layer/asymcute/asymcute.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <limits.h>
 
 #include "log.h"
diff --git a/sys/net/application_layer/dhcpv6/client.c b/sys/net/application_layer/dhcpv6/client.c
index 3f4161fb20..53facef327 100644
--- a/sys/net/application_layer/dhcpv6/client.c
+++ b/sys/net/application_layer/dhcpv6/client.c
@@ -13,6 +13,7 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
 #include <stdbool.h>
 
 #include "event.h"
diff --git a/sys/net/application_layer/emcute/emcute.c b/sys/net/application_layer/emcute/emcute.c
index 19631ba1e3..7ef7b272e0 100644
--- a/sys/net/application_layer/emcute/emcute.c
+++ b/sys/net/application_layer/emcute/emcute.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <string.h>
 
 #include "log.h"
diff --git a/sys/net/credman/credman.c b/sys/net/credman/credman.c
index fe662e5bd3..eb89b9220e 100644
--- a/sys/net/credman/credman.c
+++ b/sys/net/credman/credman.c
@@ -19,6 +19,7 @@
 #include "net/credman.h"
 #include "mutex.h"
 
+#include <assert.h>
 #include <string.h>
 
 #define ENABLE_DEBUG (0)
diff --git a/sys/net/gnrc/application_layer/dhcpv6/client.c b/sys/net/gnrc/application_layer/dhcpv6/client.c
index 3234ea744c..6788ba6871 100644
--- a/sys/net/gnrc/application_layer/dhcpv6/client.c
+++ b/sys/net/gnrc/application_layer/dhcpv6/client.c
@@ -13,6 +13,8 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
+
 #include "log.h"
 #include "net/arp.h"
 #include "net/dhcpv6.h"
diff --git a/sys/net/gnrc/link_layer/gomach/gomach_internal.c b/sys/net/gnrc/link_layer/gomach/gomach_internal.c
index eefd5a9da1..a8c3eb2d3e 100644
--- a/sys/net/gnrc/link_layer/gomach/gomach_internal.c
+++ b/sys/net/gnrc/link_layer/gomach/gomach_internal.c
@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdbool.h>
 
 #include "periph/rtt.h"
diff --git a/sys/net/gnrc/link_layer/gomach/timeout.c b/sys/net/gnrc/link_layer/gomach/timeout.c
index 686d9b82a9..c7cc8a2bd6 100644
--- a/sys/net/gnrc/link_layer/gomach/timeout.c
+++ b/sys/net/gnrc/link_layer/gomach/timeout.c
@@ -17,6 +17,8 @@
  * @}
  */
 
+#include <assert.h>
+
 #include "xtimer.h"
 #include "net/gnrc/gomach/gomach.h"
 #include "net/gnrc/gomach/timeout.h"
diff --git a/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan.c b/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan.c
index 280267caef..fc5bd3b385 100644
--- a/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan.c
+++ b/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan.c
@@ -13,6 +13,8 @@
  * @author  José Ignacio Alamos <jose.alamos@haw-hamburg.de>
  * @}
  */
+
+#include <assert.h>
 #include <stdio.h>
 #include <string.h>
 #include "net/lora.h"
diff --git a/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mcps.c b/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mcps.c
index 35e0e1c5cf..7ebd8412b6 100644
--- a/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mcps.c
+++ b/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mcps.c
@@ -12,6 +12,8 @@
  * @file
  * @author  José Ignacio Alamos <jose.alamos@haw-hamburg.de>
  */
+
+#include <assert.h>
 #include <stdio.h>
 #include <string.h>
 #include "net/lora.h"
diff --git a/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mlme.c b/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mlme.c
index 6252607c0b..9993b07f50 100644
--- a/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mlme.c
+++ b/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mlme.c
@@ -14,6 +14,8 @@
  *
  * @}
  */
+
+#include <assert.h>
 #include <stdio.h>
 #include <string.h>
 #include "net/lora.h"
diff --git a/sys/net/gnrc/link_layer/lwmac/lwmac_internal.c b/sys/net/gnrc/link_layer/lwmac/lwmac_internal.c
index 371c9430ad..d2475c50ff 100644
--- a/sys/net/gnrc/link_layer/lwmac/lwmac_internal.c
+++ b/sys/net/gnrc/link_layer/lwmac/lwmac_internal.c
@@ -19,6 +19,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdbool.h>
 
 #include "periph/rtt.h"
diff --git a/sys/net/gnrc/link_layer/lwmac/rx_state_machine.c b/sys/net/gnrc/link_layer/lwmac/rx_state_machine.c
index b7112af4cd..c706138180 100644
--- a/sys/net/gnrc/link_layer/lwmac/rx_state_machine.c
+++ b/sys/net/gnrc/link_layer/lwmac/rx_state_machine.c
@@ -19,6 +19,8 @@
  * @}
  */
 
+#include <assert.h>
+
 #include "net/gnrc.h"
 #include "net/gnrc/lwmac/lwmac.h"
 #include "net/gnrc/mac/internal.h"
diff --git a/sys/net/gnrc/link_layer/lwmac/timeout.c b/sys/net/gnrc/link_layer/lwmac/timeout.c
index a13008dcd2..67db7437ee 100644
--- a/sys/net/gnrc/link_layer/lwmac/timeout.c
+++ b/sys/net/gnrc/link_layer/lwmac/timeout.c
@@ -19,6 +19,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 
 #include "net/gnrc/lwmac/timeout.h"
diff --git a/sys/net/gnrc/link_layer/lwmac/tx_state_machine.c b/sys/net/gnrc/link_layer/lwmac/tx_state_machine.c
index 1209f92301..07e42c2513 100644
--- a/sys/net/gnrc/link_layer/lwmac/tx_state_machine.c
+++ b/sys/net/gnrc/link_layer/lwmac/tx_state_machine.c
@@ -19,6 +19,8 @@
  * @}
  */
 
+#include <assert.h>
+
 #include "periph/rtt.h"
 #include "net/gnrc.h"
 #include "net/gnrc/lwmac/lwmac.h"
diff --git a/sys/net/gnrc/link_layer/mac/internal.c b/sys/net/gnrc/link_layer/mac/internal.c
index 6bf43f3c31..f3c8076737 100644
--- a/sys/net/gnrc/link_layer/mac/internal.c
+++ b/sys/net/gnrc/link_layer/mac/internal.c
@@ -19,6 +19,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdbool.h>
 
 #include "net/gnrc.h"
diff --git a/sys/net/gnrc/link_layer/mac/timeout.c b/sys/net/gnrc/link_layer/mac/timeout.c
index 1b3f8eb5db..1fc866eb3a 100644
--- a/sys/net/gnrc/link_layer/mac/timeout.c
+++ b/sys/net/gnrc/link_layer/mac/timeout.c
@@ -19,6 +19,8 @@
  * @}
  */
 
+#include <assert.h>
+
 #include "net/gnrc.h"
 #include "net/gnrc/mac/timeout.h"
 
diff --git a/sys/net/gnrc/netapi/gnrc_netapi.c b/sys/net/gnrc/netapi/gnrc_netapi.c
index 5684e39438..dc9d827264 100644
--- a/sys/net/gnrc/netapi/gnrc_netapi.c
+++ b/sys/net/gnrc/netapi/gnrc_netapi.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 
 #include "mbox.h"
diff --git a/sys/net/gnrc/netif/ethernet/gnrc_netif_ethernet.c b/sys/net/gnrc/netif/ethernet/gnrc_netif_ethernet.c
index 19511b4502..c69201f8ed 100644
--- a/sys/net/gnrc/netif/ethernet/gnrc_netif_ethernet.c
+++ b/sys/net/gnrc/netif/ethernet/gnrc_netif_ethernet.c
@@ -15,6 +15,7 @@
  * @author  Kaspar Schleiser <kaspar@schleiser.de>
  */
 
+#include <assert.h>
 #include <string.h>
 
 #include "net/ethernet/hdr.h"
diff --git a/sys/net/gnrc/netif/gnrc_netif.c b/sys/net/gnrc/netif/gnrc_netif.c
index 4828275f67..ac7d50c4ca 100644
--- a/sys/net/gnrc/netif/gnrc_netif.c
+++ b/sys/net/gnrc/netif/gnrc_netif.c
@@ -15,6 +15,7 @@
  * @author  Oliver Hahm <oliver.hahm@inria.fr>
  */
 
+#include <assert.h>
 #include <string.h>
 #include <kernel_defines.h>
 
diff --git a/sys/net/gnrc/netif/gnrc_netif_device_type.c b/sys/net/gnrc/netif/gnrc_netif_device_type.c
index 89559e325a..34565069e0 100644
--- a/sys/net/gnrc/netif/gnrc_netif_device_type.c
+++ b/sys/net/gnrc/netif/gnrc_netif_device_type.c
@@ -14,6 +14,7 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <kernel_defines.h>
 
diff --git a/sys/net/gnrc/netif/hdr/gnrc_netif_hdr.c b/sys/net/gnrc/netif/hdr/gnrc_netif_hdr.c
index bc2d959bb4..464ac2269f 100644
--- a/sys/net/gnrc/netif/hdr/gnrc_netif_hdr.c
+++ b/sys/net/gnrc/netif/hdr/gnrc_netif_hdr.c
@@ -13,6 +13,8 @@
  * @author  Martine Lenders <mlenders@inf.fu-berlin.de>
  */
 
+#include <assert.h>
+
 #include "net/gnrc/netif/hdr.h"
 
 gnrc_pktsnip_t *gnrc_netif_hdr_build(const uint8_t *src, uint8_t src_len,
diff --git a/sys/net/gnrc/netif/init_devs/auto_init_sx127x.c b/sys/net/gnrc/netif/init_devs/auto_init_sx127x.c
index 301eb231a0..389d5abeab 100644
--- a/sys/net/gnrc/netif/init_devs/auto_init_sx127x.c
+++ b/sys/net/gnrc/netif/init_devs/auto_init_sx127x.c
@@ -17,6 +17,8 @@
  * @author      Alexandre Abadie <alexandre.abadie@inria.fr>
  */
 
+#include <assert.h>
+
 #include "log.h"
 #include "board.h"
 #include "net/gnrc/netif/lorawan_base.h"
diff --git a/sys/net/gnrc/netif/lorawan/gnrc_netif_lorawan.c b/sys/net/gnrc/netif/lorawan/gnrc_netif_lorawan.c
index a6715523af..c8d2e516d5 100644
--- a/sys/net/gnrc/netif/lorawan/gnrc_netif_lorawan.c
+++ b/sys/net/gnrc/netif/lorawan/gnrc_netif_lorawan.c
@@ -13,6 +13,8 @@
  * @author  Jose Ignacio Alamos <jose.alamos@haw-hamburg.de>
  */
 
+#include <assert.h>
+
 #include "net/gnrc/pktbuf.h"
 #include "net/gnrc/netif.h"
 #include "net/gnrc/netif/lorawan.h"
diff --git a/sys/net/gnrc/netif/pktq/gnrc_netif_pktq.c b/sys/net/gnrc/netif/pktq/gnrc_netif_pktq.c
index a1e32c602d..b8ced8b893 100644
--- a/sys/net/gnrc/netif/pktq/gnrc_netif_pktq.c
+++ b/sys/net/gnrc/netif/pktq/gnrc_netif_pktq.c
@@ -13,6 +13,8 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
+
 #include "net/gnrc/pktqueue.h"
 #include "net/gnrc/netif/conf.h"
 #include "net/gnrc/netif/internal.h"
diff --git a/sys/net/gnrc/network_layer/icmpv6/error/gnrc_icmpv6_error.c b/sys/net/gnrc/network_layer/icmpv6/error/gnrc_icmpv6_error.c
index 37755a247a..a7a6e3e585 100644
--- a/sys/net/gnrc/network_layer/icmpv6/error/gnrc_icmpv6_error.c
+++ b/sys/net/gnrc/network_layer/icmpv6/error/gnrc_icmpv6_error.c
@@ -12,6 +12,8 @@
  * @file
  */
 
+#include <assert.h>
+
 #include "net/ipv6.h"
 #include "net/gnrc/icmpv6.h"
 #include "net/gnrc/netif.h"
diff --git a/sys/net/gnrc/network_layer/icmpv6/gnrc_icmpv6.c b/sys/net/gnrc/network_layer/icmpv6/gnrc_icmpv6.c
index bc12e23088..c1ed9f0c14 100644
--- a/sys/net/gnrc/network_layer/icmpv6/gnrc_icmpv6.c
+++ b/sys/net/gnrc/network_layer/icmpv6/gnrc_icmpv6.c
@@ -15,6 +15,7 @@
  * @author      Martine Lenders <mlenders@inf.fu-berlin.de>
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <inttypes.h>
 #include <stdlib.h>
diff --git a/sys/net/gnrc/network_layer/ipv6/ext/gnrc_ipv6_ext.c b/sys/net/gnrc/network_layer/ipv6/ext/gnrc_ipv6_ext.c
index 8275bddae2..3eb7bbe5af 100644
--- a/sys/net/gnrc/network_layer/ipv6/ext/gnrc_ipv6_ext.c
+++ b/sys/net/gnrc/network_layer/ipv6/ext/gnrc_ipv6_ext.c
@@ -15,6 +15,7 @@
  * @author Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
 #include <errno.h>
 
 #include "utlist.h"
diff --git a/sys/net/gnrc/network_layer/ipv6/ext/opt/gnrc_ipv6_ext_opt.c b/sys/net/gnrc/network_layer/ipv6/ext/opt/gnrc_ipv6_ext_opt.c
index 13fd4fbcb1..0404a8af21 100644
--- a/sys/net/gnrc/network_layer/ipv6/ext/opt/gnrc_ipv6_ext_opt.c
+++ b/sys/net/gnrc/network_layer/ipv6/ext/opt/gnrc_ipv6_ext_opt.c
@@ -13,6 +13,8 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
+
 #include "net/ipv6.h"
 #include "net/ipv6/ext.h"
 #include "net/ipv6/ext/opt.h"
diff --git a/sys/net/gnrc/network_layer/ipv6/ext/rh/gnrc_ipv6_ext_rh.c b/sys/net/gnrc/network_layer/ipv6/ext/rh/gnrc_ipv6_ext_rh.c
index 8a56bad756..1084dfb346 100644
--- a/sys/net/gnrc/network_layer/ipv6/ext/rh/gnrc_ipv6_ext_rh.c
+++ b/sys/net/gnrc/network_layer/ipv6/ext/rh/gnrc_ipv6_ext_rh.c
@@ -15,6 +15,8 @@
  * @author Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
+
 #include "net/ipv6/ext/rh.h"
 #include "net/gnrc.h"
 
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/_nib-6ln.c b/sys/net/gnrc/network_layer/ipv6/nib/_nib-6ln.c
index 55ffe09b06..70dd4fbe19 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/_nib-6ln.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/_nib-6ln.c
@@ -12,6 +12,8 @@
  * @file
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
+
+#include <assert.h>
 #include <kernel_defines.h>
 
 #include "net/gnrc/netif/internal.h"
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/_nib-6lr.c b/sys/net/gnrc/network_layer/ipv6/nib/_nib-6lr.c
index b1a0f656d0..59b744bba6 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/_nib-6lr.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/_nib-6lr.c
@@ -12,6 +12,8 @@
  * @file
  * @author  Martine Lenders <mlenders@inf.fu-berlin.de>
  */
+
+#include <assert.h>
 #include <kernel_defines.h>
 
 #include "net/gnrc/ipv6/nib.h"
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/_nib-arsm.c b/sys/net/gnrc/network_layer/ipv6/nib/_nib-arsm.c
index f69162c2ed..f93f48a04e 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/_nib-arsm.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/_nib-arsm.c
@@ -12,6 +12,8 @@
  * @file
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
+
+#include <assert.h>
 #include <kernel_defines.h>
 
 #include "evtimer.h"
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/_nib-internal.c b/sys/net/gnrc/network_layer/ipv6/nib/_nib-internal.c
index bacd4f907e..f5bacd74a4 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/_nib-internal.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/_nib-internal.c
@@ -13,6 +13,7 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <string.h>
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/_nib-router.c b/sys/net/gnrc/network_layer/ipv6/nib/_nib-router.c
index 4d84e78e33..a945ec3231 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/_nib-router.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/_nib-router.c
@@ -12,6 +12,8 @@
  * @file
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
+
+#include <assert.h>
 #include <kernel_defines.h>
 
 #include "net/gnrc/ipv6/nib.h"
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/nib.c b/sys/net/gnrc/network_layer/ipv6/nib/nib.c
index 0d0b3428e5..d86810c95e 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/nib.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/nib.c
@@ -13,6 +13,7 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <kernel_defines.h>
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/nib_abr.c b/sys/net/gnrc/network_layer/ipv6/nib/nib_abr.c
index e73acdee52..2a19272fde 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/nib_abr.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/nib_abr.c
@@ -13,6 +13,7 @@
  * @author  Martine Lenders <mlenders@inf.fu-berlin.de>
  */
 
+#include <assert.h>
 #include <stdio.h>
 #include <kernel_defines.h>
 
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/nib_ft.c b/sys/net/gnrc/network_layer/ipv6/nib/nib_ft.c
index 05c6f083db..f9dd03061c 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/nib_ft.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/nib_ft.c
@@ -13,6 +13,7 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdio.h>
 
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/nib_nc.c b/sys/net/gnrc/network_layer/ipv6/nib/nib_nc.c
index 977b54a3af..ddb1ea5d28 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/nib_nc.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/nib_nc.c
@@ -13,6 +13,7 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <stdio.h>
diff --git a/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c b/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c
index a79207241a..b9c451bd03 100644
--- a/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c
+++ b/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c
@@ -13,6 +13,7 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
 #include <string.h>
 
 #include "net/gnrc/icmpv6.h"
diff --git a/sys/net/gnrc/network_layer/sixlowpan/frag/gnrc_sixlowpan_frag.c b/sys/net/gnrc/network_layer/sixlowpan/frag/gnrc_sixlowpan_frag.c
index 35f85224f8..d02761704a 100644
--- a/sys/net/gnrc/network_layer/sixlowpan/frag/gnrc_sixlowpan_frag.c
+++ b/sys/net/gnrc/network_layer/sixlowpan/frag/gnrc_sixlowpan_frag.c
@@ -32,6 +32,8 @@
 
 #if ENABLE_DEBUG
 /* For PRIu16 etc. */
+
+#include <assert.h>
 #include <inttypes.h>
 #endif
 
diff --git a/sys/net/gnrc/network_layer/sixlowpan/frag/rb/gnrc_sixlowpan_frag_rb.c b/sys/net/gnrc/network_layer/sixlowpan/frag/rb/gnrc_sixlowpan_frag_rb.c
index ac4f1546e5..2b5d066838 100644
--- a/sys/net/gnrc/network_layer/sixlowpan/frag/rb/gnrc_sixlowpan_frag_rb.c
+++ b/sys/net/gnrc/network_layer/sixlowpan/frag/rb/gnrc_sixlowpan_frag_rb.c
@@ -13,6 +13,7 @@
  * @author  Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
 #include <inttypes.h>
 #include <stdbool.h>
 
diff --git a/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c b/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
index 8a6d21c801..79283643c2 100644
--- a/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
+++ b/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
@@ -12,6 +12,8 @@
  * @file
  */
 
+#include <assert.h>
+
 #include "kernel_types.h"
 #include "net/gnrc.h"
 #include "thread.h"
diff --git a/sys/net/gnrc/priority_pktqueue/priority_pktqueue.c b/sys/net/gnrc/priority_pktqueue/priority_pktqueue.c
index c083f23be8..938475f606 100644
--- a/sys/net/gnrc/priority_pktqueue/priority_pktqueue.c
+++ b/sys/net/gnrc/priority_pktqueue/priority_pktqueue.c
@@ -19,6 +19,8 @@
  * @}
  */
 
+#include <assert.h>
+
 #include "net/gnrc/pktbuf.h"
 #include "net/gnrc/priority_pktqueue.h"
 
diff --git a/sys/net/gnrc/routing/rpl/gnrc_rpl.c b/sys/net/gnrc/routing/rpl/gnrc_rpl.c
index f5836de476..5ad711f711 100644
--- a/sys/net/gnrc/routing/rpl/gnrc_rpl.c
+++ b/sys/net/gnrc/routing/rpl/gnrc_rpl.c
@@ -15,6 +15,7 @@
  * @author  Cenk Gündoğan <cenk.guendogan@haw-hamburg.de>
  */
 
+#include <assert.h>
 #include <string.h>
 #include "kernel_defines.h"
 
diff --git a/sys/net/gnrc/routing/rpl/gnrc_rpl_control_messages.c b/sys/net/gnrc/routing/rpl/gnrc_rpl_control_messages.c
index fe078e329e..38bfd48811 100644
--- a/sys/net/gnrc/routing/rpl/gnrc_rpl_control_messages.c
+++ b/sys/net/gnrc/routing/rpl/gnrc_rpl_control_messages.c
@@ -16,6 +16,7 @@
  * @author Cenk Gündoğan <cenk.guendogan@haw-hamburg.de>
  */
 
+#include <assert.h>
 #include <string.h>
 #include "kernel_defines.h"
 
diff --git a/sys/net/gnrc/routing/rpl/gnrc_rpl_dodag.c b/sys/net/gnrc/routing/rpl/gnrc_rpl_dodag.c
index 740ec94f13..5b82fb5e79 100644
--- a/sys/net/gnrc/routing/rpl/gnrc_rpl_dodag.c
+++ b/sys/net/gnrc/routing/rpl/gnrc_rpl_dodag.c
@@ -16,6 +16,7 @@
  * @author      Cenk Gündoğan <cenk.guendogan@haw-hamburg.de>
  */
 
+#include <assert.h>
 #include <stdbool.h>
 #include <string.h>
 
diff --git a/sys/net/gnrc/routing/rpl/p2p/gnrc_rpl_p2p.c b/sys/net/gnrc/routing/rpl/p2p/gnrc_rpl_p2p.c
index b86dead0eb..02f878c6d6 100644
--- a/sys/net/gnrc/routing/rpl/p2p/gnrc_rpl_p2p.c
+++ b/sys/net/gnrc/routing/rpl/p2p/gnrc_rpl_p2p.c
@@ -14,6 +14,7 @@
  * @author  Cenk Gündoğan <cenk.guendogan@haw-hamburg.de>
  */
 
+#include <assert.h>
 #include <string.h>
 
 #include "net/icmpv6.h"
diff --git a/sys/net/gnrc/routing/rpl/srh/gnrc_rpl_srh.c b/sys/net/gnrc/routing/rpl/srh/gnrc_rpl_srh.c
index b5e53347b7..33826b1b7a 100644
--- a/sys/net/gnrc/routing/rpl/srh/gnrc_rpl_srh.c
+++ b/sys/net/gnrc/routing/rpl/srh/gnrc_rpl_srh.c
@@ -15,6 +15,7 @@
  * @author Martine Lenders <m.lenders@fu-berlin.de>
  */
 
+#include <assert.h>
 #include <string.h>
 #include "net/gnrc/netif/internal.h"
 #include "net/gnrc/ipv6/ext/rh.h"
diff --git a/sys/net/gnrc/sock/gnrc_sock.c b/sys/net/gnrc/sock/gnrc_sock.c
index c7e07cd2cd..3676433bdc 100644
--- a/sys/net/gnrc/sock/gnrc_sock.c
+++ b/sys/net/gnrc/sock/gnrc_sock.c
@@ -13,6 +13,7 @@
  * @author  Martine Lenders <mlenders@inf.fu-berlin.de>
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdlib.h>
 
diff --git a/sys/net/gnrc/sock/ip/gnrc_sock_ip.c b/sys/net/gnrc/sock/ip/gnrc_sock_ip.c
index fa56c115e8..7785720b34 100644
--- a/sys/net/gnrc/sock/ip/gnrc_sock_ip.c
+++ b/sys/net/gnrc/sock/ip/gnrc_sock_ip.c
@@ -15,6 +15,7 @@
  * @author  Martine Lenders <mlenders@inf.fu-berlin.de>
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <string.h>
 
diff --git a/sys/net/gnrc/sock/udp/gnrc_sock_udp.c b/sys/net/gnrc/sock/udp/gnrc_sock_udp.c
index 1aaa2794b7..dd3b4b466e 100644
--- a/sys/net/gnrc/sock/udp/gnrc_sock_udp.c
+++ b/sys/net/gnrc/sock/udp/gnrc_sock_udp.c
@@ -15,6 +15,7 @@
  * @author  Martine Lenders <mlenders@inf.fu-berlin.de>
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <string.h>
 
diff --git a/sys/net/gnrc/transport_layer/tcp/gnrc_tcp.c b/sys/net/gnrc/transport_layer/tcp/gnrc_tcp.c
index 1fffaf77c6..f7674dc3af 100644
--- a/sys/net/gnrc/transport_layer/tcp/gnrc_tcp.c
+++ b/sys/net/gnrc/transport_layer/tcp/gnrc_tcp.c
@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <string.h>
 #include <utlist.h>
diff --git a/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_eventloop.c b/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_eventloop.c
index 8ae01263f7..e75ad0028c 100644
--- a/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_eventloop.c
+++ b/sys/net/gnrc/transport_layer/tcp/gnrc_tcp_eventloop.c
@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <utlist.h>
 #include <errno.h>
 #include "net/af.h"
diff --git a/sys/net/gnrc/transport_layer/udp/gnrc_udp.c b/sys/net/gnrc/transport_layer/udp/gnrc_udp.c
index 7f78354d2b..c6f486d5e1 100644
--- a/sys/net/gnrc/transport_layer/udp/gnrc_udp.c
+++ b/sys/net/gnrc/transport_layer/udp/gnrc_udp.c
@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdint.h>
 #include <errno.h>
 
diff --git a/sys/net/netif/netif.c b/sys/net/netif/netif.c
index 6613018258..572cbee768 100644
--- a/sys/net/netif/netif.c
+++ b/sys/net/netif/netif.c
@@ -13,6 +13,7 @@
  * @author  Jose I. Alamos <jose.alamos@haw-hamburg.de>
  */
 
+#include <assert.h>
 #include <string.h>
 
 #include "errno.h"
diff --git a/sys/phydat/phydat.c b/sys/phydat/phydat.c
index 8fb96974c3..7dbb5dfeb2 100644
--- a/sys/phydat/phydat.c
+++ b/sys/phydat/phydat.c
@@ -20,6 +20,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdint.h>
 #include "phydat.h"
 
diff --git a/sys/pm_layered/pm.c b/sys/pm_layered/pm.c
index 0559da27d5..4f0765dd23 100644
--- a/sys/pm_layered/pm.c
+++ b/sys/pm_layered/pm.c
@@ -18,6 +18,8 @@
  * @}
  */
 
+#include <assert.h>
+
 #include "irq.h"
 #include "periph/pm.h"
 #include "pm_layered.h"
diff --git a/sys/riotboot/slot.c b/sys/riotboot/slot.c
index 472b02fc5b..fa8d3d6d9e 100644
--- a/sys/riotboot/slot.c
+++ b/sys/riotboot/slot.c
@@ -20,6 +20,8 @@
  *
  * @}
  */
+
+#include <assert.h>
 #include <string.h>
 
 #include "cpu.h"
diff --git a/sys/shell/commands/sc_gnrc_netif.c b/sys/shell/commands/sc_gnrc_netif.c
index 12dd9b4312..fd01ec52ca 100644
--- a/sys/shell/commands/sc_gnrc_netif.c
+++ b/sys/shell/commands/sc_gnrc_netif.c
@@ -18,6 +18,7 @@
  * @author      Oliver Hahm <oliver.hahm@inria.fr>
  */
 
+#include <assert.h>
 #include <ctype.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/sys/shell/commands/sc_nimble_netif.c b/sys/shell/commands/sc_nimble_netif.c
index 774ad4fb74..94b1a13ad0 100644
--- a/sys/shell/commands/sc_nimble_netif.c
+++ b/sys/shell/commands/sc_nimble_netif.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 
diff --git a/sys/suit/transport/coap.c b/sys/suit/transport/coap.c
index 02902ec255..080d6cf305 100644
--- a/sys/suit/transport/coap.c
+++ b/sys/suit/transport/coap.c
@@ -22,6 +22,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <inttypes.h>
 #include <string.h>
 
diff --git a/sys/trickle/trickle.c b/sys/trickle/trickle.c
index 80c6ca83b2..1706e8750b 100644
--- a/sys/trickle/trickle.c
+++ b/sys/trickle/trickle.c
@@ -14,6 +14,8 @@
  * @author  Cenk Gündoğan <cenk.guendogan@haw-hamburg.de>
  */
 
+#include <assert.h>
+
 #include "inttypes.h"
 #include "random.h"
 #include "trickle.h"
diff --git a/sys/uri_parser/uri_parser.c b/sys/uri_parser/uri_parser.c
index 96c2c97dee..8683da442c 100644
--- a/sys/uri_parser/uri_parser.c
+++ b/sys/uri_parser/uri_parser.c
@@ -18,6 +18,8 @@
  * @}
  */
 
+#include <assert.h>
+
 #include "uri_parser.h"
 
 #define ENABLE_DEBUG (0)
diff --git a/sys/usb/usbus/cdc/acm/cdc_acm.c b/sys/usb/usbus/cdc/acm/cdc_acm.c
index fd9ed9eae2..e88275a1d3 100644
--- a/sys/usb/usbus/cdc/acm/cdc_acm.c
+++ b/sys/usb/usbus/cdc/acm/cdc_acm.c
@@ -18,6 +18,7 @@
 
 #define USB_H_USER_IS_RIOT_INTERNAL
 
+#include <assert.h>
 #include <string.h>
 
 #include "tsrb.h"
diff --git a/sys/usb/usbus/cdc/ecm/cdc_ecm_netdev.c b/sys/usb/usbus/cdc/ecm/cdc_ecm_netdev.c
index b2d2ced4c4..c40deb42e2 100644
--- a/sys/usb/usbus/cdc/ecm/cdc_ecm_netdev.c
+++ b/sys/usb/usbus/cdc/ecm/cdc_ecm_netdev.c
@@ -17,6 +17,7 @@
 
 #define USB_H_USER_IS_RIOT_INTERNAL
 
+#include <assert.h>
 #include <string.h>
 
 #include "kernel_defines.h"
diff --git a/sys/usb/usbus/usbus.c b/sys/usb/usbus/usbus.c
index 9774f0ee4e..9ece7c1f9a 100644
--- a/sys/usb/usbus/usbus.c
+++ b/sys/usb/usbus/usbus.c
@@ -32,6 +32,7 @@
 #include "usb.h"
 #include "cpu.h"
 
+#include <assert.h>
 #include <stdint.h>
 #include <string.h>
 #include <errno.h>
diff --git a/sys/usb/usbus/usbus_fmt.c b/sys/usb/usbus/usbus_fmt.c
index f851619224..aced79cc11 100644
--- a/sys/usb/usbus/usbus_fmt.c
+++ b/sys/usb/usbus/usbus_fmt.c
@@ -18,6 +18,7 @@
 
 #define USB_H_USER_IS_RIOT_INTERNAL
 
+#include <assert.h>
 #include <string.h>
 #include <stdio.h>
 #include "usb/descriptor.h"
diff --git a/sys/xtimer/xtimer_core.c b/sys/xtimer/xtimer_core.c
index 20a67397b8..8031fea73f 100644
--- a/sys/xtimer/xtimer_core.c
+++ b/sys/xtimer/xtimer_core.c
@@ -22,6 +22,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdint.h>
 #include <string.h>