diff --git a/libc/include/bits/ioctl.h b/libc/include/bits/ioctl.h
index 745bbf0..3357c1b 100644
--- a/libc/include/bits/ioctl.h
+++ b/libc/include/bits/ioctl.h
@@ -51,7 +51,8 @@
  * FIXME: __has_extension is more or less a clang version check. Remove it when
  * we don't need to support old clang code.
  */
-#if __has_extension(overloadable_unmarked) && !defined(BIONIC_IOCTL_NO_SIGNEDNESS_OVERLOAD)
+#if defined(__clang__) && __has_extension(overloadable_unmarked) && \
+  !defined(BIONIC_IOCTL_NO_SIGNEDNESS_OVERLOAD)
 /* enable_if(1) just exists to break overloading ties. */
 int ioctl(int __fd, unsigned __request, ...) __overloadable __enable_if(1, "") __RENAME(ioctl);
 #endif