diff --git a/leaflet.rotatedMarker.js b/leaflet.rotatedMarker.js
index eb5c2b7..479e7b4 100644
--- a/leaflet.rotatedMarker.js
+++ b/leaflet.rotatedMarker.js
@@ -37,7 +37,7 @@
                     this._icon.style[L.DomUtil.TRANSFORM] = 'rotate(' + this.options.rotationAngle + 'deg)';
                 } else {
                     // for modern browsers, prefer the 3D accelerated version
-                    this._icon.style[L.DomUtil.TRANSFORM] += ' rotateZ(' + this.options.rotationAngle + 'deg)';
+                    this._icon.style[L.DomUtil.TRANSFORM] = ' rotateZ(' + this.options.rotationAngle + 'deg)';
                 }
             }
         },