diff --git a/src/css.js b/src/css.js
index 6abcc956..ddd42b4b 100644
--- a/src/css.js
+++ b/src/css.js
@@ -167,7 +167,7 @@ jQuery.extend({
 
 				// Put in the new values to get a computed value out
 				elem.runtimeStyle.left = elem.currentStyle.left;
-				style.left = ret || 0;
+				style.left = camelCase === "fontSize" ? "1em" : (ret || 0);
 				ret = style.pixelLeft + "px";
 
 				// Revert the changed values
@@ -212,4 +212,4 @@ if ( jQuery.expr && jQuery.expr.filters ) {
 	jQuery.expr.filters.visible = function(elem){
 		return !jQuery.expr.filters.hidden(elem);
 	};
-}
\ No newline at end of file
+}
diff --git a/test/data/testsuite.css b/test/data/testsuite.css
index 7a162431..5cc78282 100644
--- a/test/data/testsuite.css
+++ b/test/data/testsuite.css
@@ -103,3 +103,7 @@ div.chain.out { background: green; }
 div.chain.out div { background: red; display: none; }
 
 div#show-tests * { display: none; }
+
+#nothiddendiv { font-size: 16px; }
+#nothiddendivchild.em { font-size: 2em; }
+#nothiddendivchild.prct { font-size: 150%; }
diff --git a/test/unit/css.js b/test/unit/css.js
index 649db596..beac04a8 100644
--- a/test/unit/css.js
+++ b/test/unit/css.js
@@ -1,7 +1,7 @@
 module("css");
 
 test("css(String|Hash)", function() {
-	expect(23);
+	expect(27);
 
 	equals( jQuery('#main').css("display"), 'none', 'Check for css property "display"');
 
@@ -38,6 +38,17 @@ test("css(String|Hash)", function() {
 	equals( jQuery('#empty').css('opacity'), '0', "Assert opacity is accessible via filter property set in stylesheet in IE" );
 	jQuery('#empty').css({ opacity: '1' });
 	equals( jQuery('#empty').css('opacity'), '1', "Assert opacity is taken from style attribute when set vs stylesheet in IE with filters" );
+
+	var div = jQuery('#nothiddendiv'), child = jQuery('#nothiddendivchild');
+
+	equals( parseInt(div.css("fontSize")), 16, "Verify fontSize px set." );
+	equals( parseInt(child.css("fontSize")), 16, "Verify fontSize px set." );
+
+	child.attr("class", "em");
+	equals( parseInt(child.css("fontSize")), 32, "Verify fontSize em set." );
+
+	child.attr("class", "prct");
+	equals( parseInt(child.css("fontSize")), 24, "Verify fontSize % set." );
 });
 
 test("css(String, Object)", function() {