diff --git a/include/SDL_stdinc.h b/include/SDL_stdinc.h
index 3f01d56a5513e..9fa348826a26d 100644
--- a/include/SDL_stdinc.h
+++ b/include/SDL_stdinc.h
@@ -749,6 +749,9 @@ size_t wcslcpy(wchar_t *dst, const wchar_t *src, size_t size);
 size_t wcslcat(wchar_t *dst, const wchar_t *src, size_t size);
 #endif
 
+/* strdup is not ANSI but POSIX, and its prototype might be hidden... */
+char *strdup(const char *str);
+
 /* Starting LLVM 16, the analyser errors out if these functions do not have
    their prototype defined (clang-diagnostic-implicit-function-declaration) */
 #include <stdlib.h>