diff --git a/configure.ac b/configure.ac
index 67e2a98f2..93fb7e101 100644
--- a/configure.ac
+++ b/configure.ac
@@ -415,9 +415,9 @@ CAIRO_ENABLE(test_surfaces, test surfaces, no)
 dnl ===========================================================================
 
 CAIRO_ENABLE_SURFACE_BACKEND(image, image, always, [
-  pixman_REQUIRES="pixman-1 >= 0.11.2"
-  PKG_CHECK_MODULES(pixman, $pixman_REQUIRES, , [AC_MSG_RESULT(no)
-  use_image="no (requires $pixman_REQUIRES http://cairographics.org/releases/)"])
+  image_REQUIRES="pixman-1 >= 0.11.2"
+  PKG_CHECK_MODULES(pixman, $image_REQUIRES, , [AC_MSG_RESULT(no)
+  use_image="no (requires $image_REQUIRES http://cairographics.org/releases/)"])
 ])
 
 dnl ===========================================================================