diff --git a/mlibc/include/string.h b/mlibc/include/string.h
index 4d706a7b..48f5e466 100644
--- a/mlibc/include/string.h
+++ b/mlibc/include/string.h
@@ -50,6 +50,7 @@ int strcmp (char const*, char const*);
 char *strcpy (char *dest, char const *src);
 int strncmp (char const*, char const*, size_t);
 char *strrchr (char const *s, int c);
+char *strstr (char const *haystack, char const *needle);
 
 #endif // ! (__GNUC__ && POSIX)
 
diff --git a/mlibc/libc-mes+tcc.c b/mlibc/libc-mes+tcc.c
index f038949b..19353555 100644
--- a/mlibc/libc-mes+tcc.c
+++ b/mlibc/libc-mes+tcc.c
@@ -172,6 +172,12 @@ strrchr (char const *s, int c)
   return 0;
 }
 
+char *
+strstr (char const *haystack, char const *needle)
+{
+  return 0;
+}
+
 long
 strtol (char const *nptr, char **endptr, int base)
 {