diff --git a/src/test/SDL_test_fuzzer.c b/src/test/SDL_test_fuzzer.c
index aff4a1c2e..9fad17858 100644
--- a/src/test/SDL_test_fuzzer.c
+++ b/src/test/SDL_test_fuzzer.c
@@ -34,6 +34,7 @@
 #define UINT32_MAX  ~(Uint32)0
 #define UINT64_MAX  ~(Uint64)0
 #else
+#define _GNU_SOURCE
 #include <stdint.h>
 #endif
 #include <stdio.h>