diff --git a/tests/benchmarks/footprints/src/libc.c b/tests/benchmarks/footprints/src/libc.c
index 48b8eb823cf..7cf71239f4c 100644
--- a/tests/benchmarks/footprints/src/libc.c
+++ b/tests/benchmarks/footprints/src/libc.c
@@ -4,6 +4,9 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#undef _POSIX_C_SOURCE
+#define _POSIX_C_SOURCE 200809L
+
 #include <zephyr/kernel.h>
 #include <ksched.h>