diff --git a/libc/include/strings.h b/libc/include/strings.h
index c2e0a5e..11f3213 100644
--- a/libc/include/strings.h
+++ b/libc/include/strings.h
@@ -55,11 +55,11 @@
 #endif
 
 #if !defined(__i386__) || __ANDROID_API__ >= __ANDROID_API_J_MR2__
-int ffs(int __i) __INTRODUCED_IN_X86(18);
+int ffs(int) __INTRODUCED_IN_X86(18);
 #endif
 
 __END_DECLS
 
 #include <android/legacy_strings_inlines.h>
 
-#endif
+#endif /* !defined(_STRINGS_H_) */