diff --git a/tests/bitarithm_timings/main.c b/tests/bitarithm_timings/main.c
index 6cdec07bc4..a3f91b83f2 100644
--- a/tests/bitarithm_timings/main.c
+++ b/tests/bitarithm_timings/main.c
@@ -29,6 +29,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdint.h>
 #include <stdatomic.h>
 #include <stdio.h>
diff --git a/tests/c11_atomics_cpp_compat/main.c b/tests/c11_atomics_cpp_compat/main.c
index d727a4ec7b..6cbbcb0563 100644
--- a/tests/c11_atomics_cpp_compat/main.c
+++ b/tests/c11_atomics_cpp_compat/main.c
@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
diff --git a/tests/candev/main.c b/tests/candev/main.c
index 65451718d9..c5bce70a0f 100644
--- a/tests/candev/main.c
+++ b/tests/candev/main.c
@@ -21,6 +21,7 @@
 
 #define ENABLE_DEBUG (0)
 
+#include <assert.h>
 #include <debug.h>
 #include <errno.h>
 #include <isrpipe.h>
diff --git a/tests/driver_lis2dh12/main.c b/tests/driver_lis2dh12/main.c
index 60c40c0674..ef7b936442 100644
--- a/tests/driver_lis2dh12/main.c
+++ b/tests/driver_lis2dh12/main.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdio.h>
 
 #include "fmt.h"
diff --git a/tests/gnrc_ipv6_ext_frag/main.c b/tests/gnrc_ipv6_ext_frag/main.c
index 5942474212..16409baf16 100644
--- a/tests/gnrc_ipv6_ext_frag/main.c
+++ b/tests/gnrc_ipv6_ext_frag/main.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/tests/gnrc_sock_ip/main.c b/tests/gnrc_sock_ip/main.c
index 5f365423e6..baab17bdcd 100644
--- a/tests/gnrc_sock_ip/main.c
+++ b/tests/gnrc_sock_ip/main.c
@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
diff --git a/tests/gnrc_sock_udp/main.c b/tests/gnrc_sock_udp/main.c
index 1905897e8d..d211cada5b 100644
--- a/tests/gnrc_sock_udp/main.c
+++ b/tests/gnrc_sock_udp/main.c
@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
diff --git a/tests/ieee802154_hal/main.c b/tests/ieee802154_hal/main.c
index 990e4a90ac..22f57af9cd 100644
--- a/tests/ieee802154_hal/main.c
+++ b/tests/ieee802154_hal/main.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdio.h>
 
 #include "common.h"
diff --git a/tests/ieee802154_submac/main.c b/tests/ieee802154_submac/main.c
index af116636db..91f0cf67d8 100644
--- a/tests/ieee802154_submac/main.c
+++ b/tests/ieee802154_submac/main.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
diff --git a/tests/lwip_sock_ip/main.c b/tests/lwip_sock_ip/main.c
index 5df5eff04d..5cf9fcce2d 100644
--- a/tests/lwip_sock_ip/main.c
+++ b/tests/lwip_sock_ip/main.c
@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
diff --git a/tests/lwip_sock_udp/main.c b/tests/lwip_sock_udp/main.c
index e5564f1a48..86ec985308 100644
--- a/tests/lwip_sock_udp/main.c
+++ b/tests/lwip_sock_udp/main.c
@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
diff --git a/tests/thread_msg_bus/main.c b/tests/thread_msg_bus/main.c
index 9e139ddc2b..1a530fadee 100644
--- a/tests/thread_msg_bus/main.c
+++ b/tests/thread_msg_bus/main.c
@@ -18,6 +18,7 @@
  * @}
  */
 
+#include <assert.h>
 #include <stdio.h>
 #include <inttypes.h>