diff --git a/src/tooltip.js b/src/tooltip.js
index 6b0a7d4..75d1416 100644
--- a/src/tooltip.js
+++ b/src/tooltip.js
@@ -75,7 +75,7 @@ c3_chart_internal_fn.tooltipPosition = function (dataToShow, tWidth, tHeight, el
         }
 
         if (tooltipRight > chartRight) {
-            // 20 is needed for Firefox to keep tooletip width
+            // 20 is needed for Firefox to keep tooltip width
             tooltipLeft -= tooltipRight - chartRight + 20;
         }
         if (tooltipTop + tHeight > $$.currentHeight) {