diff --git a/src/lib/style-util.html b/src/lib/style-util.html
index 82c6eeec41..86ce6a12dd 100644
--- a/src/lib/style-util.html
+++ b/src/lib/style-util.html
@@ -165,7 +165,7 @@
       },
 
       cssFromModules: function(moduleIds, warnIfNotFound) {
-        var modules = moduleIds.trim().split(' ');
+        var modules = moduleIds.trim().split(/\s+/);
         var cssText = '';
         for (var i=0; i < modules.length; i++) {
           cssText += this.cssFromModule(modules[i], warnIfNotFound);
diff --git a/test/unit/custom-style-import.html b/test/unit/custom-style-import.html
index b5e4828960..3771b61212 100644
--- a/test/unit/custom-style-import.html
+++ b/test/unit/custom-style-import.html
@@ -20,7 +20,8 @@
 
 <link rel="import" href="sub/style-import.html">
 
-<style is="custom-style" include="shared-style style-import">
+<style is="custom-style" include="shared-style style-import
+    style-import2">
   :root {
 
     --import-mixin: {
diff --git a/test/unit/custom-style.html b/test/unit/custom-style.html
index 25990dc06f..7b34a2f39a 100644
--- a/test/unit/custom-style.html
+++ b/test/unit/custom-style.html
@@ -507,6 +507,11 @@
         assert.include(url, 'sub/google.png');
       });
 
+      test('style paths can have arbitrary whitespace', function() {
+        var foo = document.querySelector('.foo');
+        assertComputed(foo, '4px', 'width');
+      });
+
       test('property in /deep/ rule applied via document scope inheritance', function() {
         assertComputed(xFoo.$.deep, '6px');
       });
diff --git a/test/unit/sub/style-import.html b/test/unit/sub/style-import.html
index b46759d37e..5a8d6c6a00 100644
--- a/test/unit/sub/style-import.html
+++ b/test/unit/sub/style-import.html
@@ -8,4 +8,14 @@
       }
     </style>
   </template>
-</dom-module>
\ No newline at end of file
+</dom-module>
+
+<dom-module id="style-import2">
+  <template>
+    <style>
+      .foo {
+        width: 4px;
+      }
+    </style>
+  </template>
+</dom-module>