diff --git a/lib/codemirror.js b/lib/codemirror.js
index <HASH>..<HASH> 100644
--- a/lib/codemirror.js
+++ b/lib/codemirror.js
@@ -877,9 +877,10 @@ window.CodeMirror = (function() {
     clearInterval(display.blinker);
     var on = true;
     display.cursor.style.visibility = display.otherCursor.style.visibility = "";
-    display.blinker = setInterval(function() {
-      display.cursor.style.visibility = display.otherCursor.style.visibility = (on = !on) ? "" : "hidden";
-    }, cm.options.cursorBlinkRate);
+    if (cm.options.cursorBlinkRate > 0)
+      display.blinker = setInterval(function() {
+        display.cursor.style.visibility = display.otherCursor.style.visibility = (on = !on) ? "" : "hidden";
+      }, cm.options.cursorBlinkRate);
   }
 
   // HIGHLIGHT WORKER
Added ability to disable cursor blinking.

When the cursor blink rate is zero (or negative) the cursor should not
blink.  Previously, it was blinking as fast as possible when the rate
was zero.