diff --git a/AppKit/Platform/DOM/CPPlatformString.j b/AppKit/Platform/DOM/CPPlatformString.j
index 1e520dd7f..3bce7f82d 100644
--- a/AppKit/Platform/DOM/CPPlatformString.j
+++ b/AppKit/Platform/DOM/CPPlatformString.j
@@ -144,7 +144,9 @@ var DOMFixedWidthSpanElement    = nil,
         span.style.width = ROUND(aWidth) + "px";
     }
 
-    span.style.font = [(aFont || DefaultFont) cssString];
+    var effectiveFontCSSString = [(aFont || DefaultFont) cssString];
+    if (span.style.font !== effectiveFontCSSString)
+        span.style.font = effectiveFontCSSString;
 
     if (CPFeatureIsCompatible(CPJavaScriptInnerTextFeature))
         span.innerText = aString;