diff --git a/Xfuncproto.h.in b/Xfuncproto.h.in
index 5daa83e..8556c27 100644
--- a/Xfuncproto.h.in
+++ b/Xfuncproto.h.in
@@ -79,6 +79,9 @@ in this Software without prior written authorization from The Open Group.
 #ifndef __has_attribute
 # define __has_attribute(x) 0  /* Compatibility with non-clang compilers. */
 #endif
+#ifndef __has_feature
+# define __has_feature(x) 0    /* Compatibility with non-clang compilers. */
+#endif
 
 /* Added in X11R6.9, so available in any version of modular xproto */
 #if __has_attribute(__sentinel__) || (defined(__GNUC__) && (__GNUC__ >= 4))