diff --git a/src/Layout.c b/src/Layout.c
index 776e500f..efdb4181 100644
--- a/src/Layout.c
+++ b/src/Layout.c
@@ -276,6 +276,10 @@ float getDimWithMargin(css_node_t *node, css_flex_direction_t axis) {
     getMargin(node, trailing[axis]);
 }
 
+bool isDimDefined(css_node_t *node, css_flex_direction_t axis) {
+  return !isUndefined(node->style.dimensions[dim[axis]]);
+}
+
 float getPosition(css_node_t *node, css_position_t pos) {
   float result = node->style.position[pos];
   if (!isUndefined(result)) {
@@ -294,19 +298,18 @@ float getRelativePosition(css_node_t *node, css_flex_direction_t axis) {
   return getPosition(node, trailing[axis]);
 }
 
-
 void layoutNode(css_node_t *node) {
   css_flex_direction_t mainAxis = getFlexDirection(node);
   css_flex_direction_t crossAxis = mainAxis == CSS_FLEX_DIRECTION_ROW ?
       CSS_FLEX_DIRECTION_COLUMN :
       CSS_FLEX_DIRECTION_ROW;
 
-  bool mainDimInStyle = !isUndefined(node->style.dimensions[dim[mainAxis]]);
+  bool mainDimInStyle = isDimDefined(node, mainAxis);
   if (isUndefined(node->layout.dimensions[dim[mainAxis]]) && mainDimInStyle) {
     node->layout.dimensions[dim[mainAxis]] = node->style.dimensions[dim[mainAxis]];
   }
 
-  bool crossDimInStyle = !isUndefined(node->style.dimensions[dim[crossAxis]]);
+  bool crossDimInStyle = isDimDefined(node, crossAxis);
   if (isUndefined(node->layout.dimensions[dim[crossAxis]]) && crossDimInStyle) {
     node->layout.dimensions[dim[crossAxis]] = node->style.dimensions[dim[crossAxis]];
   }
diff --git a/src/Layout.js b/src/Layout.js
index 177b8da0..60dc3249 100755
--- a/src/Layout.js
+++ b/src/Layout.js
@@ -88,6 +88,11 @@ function computeLayout(node) {
       getMargin(node, trailing[axis]);
   }
 
+  function isDimDefined(node, axis) {
+    return !isUndefined(node.style[dim[axis]]);
+  }
+
+
   function getPosition(node, pos) {
     if (pos in node.style) {
       return node.style[pos];
@@ -141,12 +146,12 @@ function computeLayout(node) {
       CSS_FLEX_DIRECTION_COLUMN :
       CSS_FLEX_DIRECTION_ROW;
 
-    var mainDimInStyle = dim[mainAxis] in node.style;
+    var mainDimInStyle = isDimDefined(node, mainAxis);
     if (isUndefined(node.layout[dim[mainAxis]]) && mainDimInStyle) {
       node.layout[dim[mainAxis]] = node.style[dim[mainAxis]];
     }
 
-    var crossDimInStyle = dim[crossAxis] in node.style;
+    var crossDimInStyle = isDimDefined(node, crossAxis);
     if (isUndefined(node.layout[dim[crossAxis]]) && crossDimInStyle) {
       node.layout[dim[crossAxis]] = node.style[dim[crossAxis]];
     }