diff --git a/configure b/configure
index 25a021368..30c6bc19e 100755
--- a/configure
+++ b/configure
@@ -12940,22 +12940,7 @@ esac
 
   fi
 
-  for ac_header in dispatch.h
-do :
-  ac_fn_c_check_header_mongrel "$LINENO" "dispatch.h" "ac_cv_header_dispatch_h" "$ac_includes_default"
-if test "x$ac_cv_header_dispatch_h" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_DISPATCH_H 1
-_ACEOF
- have_dispatch=yes
-else
-  have_dispatch=no
-fi
-
-done
-
-  if test "$have_dispatch" = "no"; then
-    for ac_header in dispatch/dispatch.h
+  for ac_header in dispatch/dispatch.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "dispatch/dispatch.h" "ac_cv_header_dispatch_dispatch_h" "$ac_includes_default"
 if test "x$ac_cv_header_dispatch_dispatch_h" = xyes; then :
@@ -12969,6 +12954,7 @@ fi
 
 done
 
+  if test "$have_dispatch" = "yes"; then
     # check for private header which includes runloop integration functions in
     # the Swift corelibs libdispatch release
     for ac_header in dispatch/private.h
@@ -12981,6 +12967,21 @@ _ACEOF
 
 fi
 
+done
+
+  else
+    for ac_header in dispatch.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "dispatch.h" "ac_cv_header_dispatch_h" "$ac_includes_default"
+if test "x$ac_cv_header_dispatch_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_DISPATCH_H 1
+_ACEOF
+ have_dispatch=yes
+else
+  have_dispatch=no
+fi
+
 done
 
   fi
diff --git a/configure.ac b/configure.ac
index 6dd78ce76..9f9bc5ef6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3392,12 +3392,13 @@ if test $enable_libdispatch = yes; then
     GS_ADD_LIBRARY_PATH([${dispatch_libdir}])
   fi
 
-  AC_CHECK_HEADERS(dispatch.h, have_dispatch=yes, have_dispatch=no)
-  if test "$have_dispatch" = "no"; then
-    AC_CHECK_HEADERS(dispatch/dispatch.h, have_dispatch=yes, have_dispatch=no)
+  AC_CHECK_HEADERS(dispatch/dispatch.h, have_dispatch=yes, have_dispatch=no)
+  if test "$have_dispatch" = "yes"; then
     # check for private header which includes runloop integration functions in
     # the Swift corelibs libdispatch release
     AC_CHECK_HEADERS(dispatch/private.h)
+  else
+    AC_CHECK_HEADERS(dispatch.h, have_dispatch=yes, have_dispatch=no)
   fi
   if test "$have_dispatch" = "yes"; then
     AC_CHECK_LIB(dispatch, dispatch_queue_create, have_dispatch=yes, have_dispatch=no)