diff --git a/src/extras/core/Curve.js b/src/extras/core/Curve.js
index 9c50cf42046e4c68077634f805bf2a2dc84f7953..1e20cca393d8217de7bf33505b6667b37abfb9bf 100644
--- a/src/extras/core/Curve.js
+++ b/src/extras/core/Curve.js
@@ -67,7 +67,7 @@ Curve.prototype = {
 
 	getPoints: function ( divisions ) {
 
-		if ( ! divisions ) divisions = 5;
+		if ( isNaN( divisions ) ) divisions = 5;
 
 		var points = [];
 
@@ -85,7 +85,7 @@ Curve.prototype = {
 
 	getSpacedPoints: function ( divisions ) {
 
-		if ( ! divisions ) divisions = 5;
+		if ( isNaN( divisions ) ) divisions = 5;
 
 		var points = [];
 
@@ -112,7 +112,7 @@ Curve.prototype = {
 
 	getLengths: function ( divisions ) {
 
-		if ( ! divisions ) divisions = ( this.__arcLengthDivisions ) ? ( this.__arcLengthDivisions ) : 200;
+		if ( isNaN( divisions ) ) divisions = ( this.__arcLengthDivisions ) ? ( this.__arcLengthDivisions ) : 200;
 
 		if ( this.cacheArcLengths
 			&& ( this.cacheArcLengths.length === divisions + 1 )
diff --git a/src/extras/core/CurvePath.js b/src/extras/core/CurvePath.js
index 8ae48b022d6f426063cf00230916a320bda2360c..620e9cf3e014fcea26b070f7eb21fc2e32fadd67 100644
--- a/src/extras/core/CurvePath.js
+++ b/src/extras/core/CurvePath.js
@@ -139,7 +139,7 @@ CurvePath.prototype = Object.assign( Object.create( Curve.prototype ), {
 
 	getSpacedPoints: function ( divisions ) {
 
-		if ( ! divisions ) divisions = 40;
+		if ( isNaN( divisions ) ) divisions = 40;
 
 		var points = [];