diff --git a/src/showdown.js b/src/showdown.js
index a2ca4c7..5b5c4e0 100644
--- a/src/showdown.js
+++ b/src/showdown.js
@@ -219,11 +219,13 @@ if (converter_options && converter_options.extensions) {
 
   var self = this;
   
-  // if a string is given like this new Showdown.converter({ extensions: 'github' })
-  // Ensure it can traverse the extensions list
-  if(typeof converter_options.extensions === 'string'){
-  	converter_options.extensions = [converter_options.extensions];
-  }
+  var extensionList = converter_options.extensions;
+
+	// if a string is given like this new Showdown.converter({ extensions: 'github' })
+	// Ensure it can traverse the extensions list
+	if(typeof extensionList === 'string'){
+	    converter_options.extensions = [extensionList];
+	}
 
 	// Iterate over each plugin
 	Showdown.forEach(converter_options.extensions, function(plugin){