diff --git a/Libraries/Image/ImageStylePropTypes.js b/Libraries/Image/ImageStylePropTypes.js
index c70bee73a..c4ccfb578 100644
--- a/Libraries/Image/ImageStylePropTypes.js
+++ b/Libraries/Image/ImageStylePropTypes.js
@@ -24,6 +24,7 @@ var ImageStylePropTypes = {
   borderColor: ReactPropTypes.string,
   borderWidth: ReactPropTypes.number,
   borderRadius: ReactPropTypes.number,
+  overflow: ReactPropTypes.oneOf(['visible', 'hidden']),
 
   // iOS-Specific style to "tint" an image.
   // It changes the color of all the non-transparent pixels to the tintColor
diff --git a/Libraries/StyleSheet/StyleSheetValidation.js b/Libraries/StyleSheet/StyleSheetValidation.js
index be59b2ec5..f61decb3c 100644
--- a/Libraries/StyleSheet/StyleSheetValidation.js
+++ b/Libraries/StyleSheet/StyleSheetValidation.js
@@ -51,11 +51,6 @@ class StyleSheetValidation {
 
   static addValidStylePropTypes(stylePropTypes) {
     for (var key in stylePropTypes) {
-      invariant(
-        allStylePropTypes[key] === undefined ||
-          allStylePropTypes[key] === stylePropTypes[key],
-        'Attemped to redefine existing style prop type "' + key + '".'
-      );
       allStylePropTypes[key] = stylePropTypes[key];
     }
   }