diff --git a/Userland/Libraries/LibC/stdlib.h b/Userland/Libraries/LibC/stdlib.h
index 56f067d8c1..b67030e1c3 100644
--- a/Userland/Libraries/LibC/stdlib.h
+++ b/Userland/Libraries/LibC/stdlib.h
@@ -10,8 +10,6 @@
 #include <sys/cdefs.h>
 #include <sys/types.h>
 
-__attribute__((warn_unused_result)) int __generate_unique_filename(char* pattern);
-
 __BEGIN_DECLS
 
 #define EXIT_SUCCESS 0