Index: Gruntfile.js
===================================================================
--- Gruntfile.js	(revision 37173)
+++ Gruntfile.js	(working copy)
@@ -699,7 +699,7 @@
 			}
 			if ( /src.*\.css/.test( filesModified ) ) {
 				grunt.log.write( 'CSS source files modified. CSS tests will be run.\n');
-				taskList = taskList.concat( ['postcss:core'] );
+				taskList = taskList.concat( ['precommit:css'] );
 			}
 			if ( /.*\.php/.test( filesModified ) ) {
 				grunt.log.write( 'PHP source files modified. PHP tests will be run.\n');