--- a/core/storagemanager.lua	Wed Aug 31 11:42:03 2016 +0100
+++ b/core/storagemanager.lua	Wed Aug 31 11:45:06 2016 +0100
@@ -153,12 +153,12 @@
 		if err == "unsupported-store" then
 			if typ == "map" then -- Use shim on top of keyval store
 				log("debug", "map storage driver unavailable, using shim on top of keyval store.");
-				return create_map_shim(host, store);
+				ret, err = create_map_shim(host, store);
+			else
+				log("debug", "Storage driver %s does not support store %s (%s), falling back to null driver",
+					driver_name, store, typ or "<nil>");
+				ret, err = null_storage_driver, nil;
 			end
-			log("debug", "Storage driver %s does not support store %s (%s), falling back to null driver",
-				driver_name, store, typ or "<nil>");
-			ret = null_storage_driver;
-			err = nil;
 		end
 	end
 	return ret, err;