--- configure
+++ configure
@@ -19046,6 +19046,8 @@
 
 	else
 		# On iOS CoreText and CoreGraphics are stand-alone frameworks
+               # Forget the cache failure to find CTFontRef above
+               unset ac_cv_type_CTFontRef
 		if test "x$have_coretext" != "xtrue"; then
 			ac_fn_c_check_type "$LINENO" "CTFontRef" "ac_cv_type_CTFontRef" "#include <CoreText/CoreText.h>
 "