diff --git a/src/style/Style.js b/src/style/Style.js
index cffee723..33a08d48 100644
--- a/src/style/Style.js
+++ b/src/style/Style.js
@@ -288,11 +288,11 @@ var Style = Base.extend(new function() {
 		// To prevent an obscure iOS 7 crash, we have to convert the size to a
 		// string first before passing it to the regular expression.
 		// The following nonsensical statement would also prevent the bug,
-		// prooving that the issue is not the regular expression itself, but
+		// proving that the issue is not the regular expression itself, but
 		// something deeper down in the optimizer:
 		// `if (size === 0) size = 0;`
 		return this.getFontWeight()
-				+ ' ' + fontSize + (/\w/i.test(fontSize + '') ? ' ' : 'px ')
+				+ ' ' + fontSize + (/\[a-z]/i.test(fontSize + '') ? ' ' : 'px ')
 				+ this.getFontFamily();
 	},