diff --git a/mode/clojure/clojure.js b/mode/clojure/clojure.js
index ce389927db339cc1bd325cc3bf1558589353b04c..84f6073fd52f7a408970d8739a60534e3b7fb89e 100644
--- a/mode/clojure/clojure.js
+++ b/mode/clojure/clojure.js
@@ -70,7 +70,7 @@ CodeMirror.defineMode("clojure", function (config, mode) {
         }
 
         // leading sign
-        if ( ch == '+' || ch == '-' ) {
+        if ( ( ch == '+' || ch == '-' ) && ( tests.digit.test(stream.peek()) ) ) {
           stream.eat(tests.sign);
           ch = stream.next();
         }