diff --git a/ChangeLog b/ChangeLog
index 11a90b48..3a46692a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,7 @@
 12/9/11 started 7.26.4
 - fallback vips_init() 
 - im_openout() compat stub was wrong, breaking ruby-vips
+- vips_class_map_concrete_all() needed a compat macro too
 
 10/8/11 started 7.26.3
 - don't use G_VALUE_COLLECT_INIT(), many platforms do not have a glib this
diff --git a/libvips/include/vips/vips7compat.h b/libvips/include/vips/vips7compat.h
index b24413bc..30a81a20 100644
--- a/libvips/include/vips/vips7compat.h
+++ b/libvips/include/vips/vips7compat.h
@@ -486,6 +486,10 @@ int im_wrapmany( VipsImage **in, VipsImage *out,
 #define im_concurrency_set vips_concurrency_set
 #define im_concurrency_get vips_concurrency_get
 
+/* ruby-vips uses this
+ */
+#define vips_class_map_concrete_all vips_class_map_all
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus*/