diff --git a/mode/sparql/sparql.js b/mode/sparql/sparql.js
index 5e68f5670d..6d928b5cde 100644
--- a/mode/sparql/sparql.js
+++ b/mode/sparql/sparql.js
@@ -33,6 +33,9 @@ CodeMirror.defineMode("sparql", function(config) {
                              "true", "false", "with",
                              "data", "copy", "to", "move", "add", "create", "drop", "clear", "load", "into"]);
   var operatorChars = /[*+\-<>=&|\^\/!\?]/;
+  var PN_CHARS = "[A-Za-z_\\-0-9]";
+  var PREFIX_START = new RegExp("[A-Za-z]");
+  var PREFIX_REMAINDER = new RegExp("((" + PN_CHARS + "|\\.)*(" + PN_CHARS + "))?:");
 
   function tokenBase(stream, state) {
     var ch = stream.next();
@@ -71,20 +74,18 @@ CodeMirror.defineMode("sparql", function(config) {
       stream.eatWhile(/[a-z\d\-]/i);
       return "meta";
     }
-    else {
-      stream.eatWhile(/[_\w\d]/);
-      if (stream.eat(":")) {
+    else if (PREFIX_START.test(ch) && stream.match(PREFIX_REMAINDER)) {
         eatPnLocal(stream);
         return "atom";
-      }
-      var word = stream.current();
-      if (ops.test(word))
-        return "builtin";
-      else if (keywords.test(word))
-        return "keyword";
-      else
-        return "variable";
     }
+    stream.eatWhile(/[_\w\d]/);
+    var word = stream.current();
+    if (ops.test(word))
+      return "builtin";
+    else if (keywords.test(word))
+      return "keyword";
+    else
+      return "variable";
   }
 
   function eatPnLocal(stream) {