diff --git a/lib/dgram.js b/lib/dgram.js
index 2e8071ca121..ee239558199 100644
--- a/lib/dgram.js
+++ b/lib/dgram.js
@@ -260,7 +260,9 @@ Socket.prototype.addMembership = function(multicastAddress,
     throw new Error('multicast address must be specified');
   }
 
-  return this._handle.addMembership(multicastAddress, interfaceAddress);
+  if (this._handle.addMembership(multicastAddress, interfaceAddress)) {
+    throw new errnoException(errno, 'addMembership');
+  }
 };
 
 
@@ -272,7 +274,9 @@ Socket.prototype.dropMembership = function(multicastAddress,
     throw new Error('multicast address must be specified');
   }
 
-  return this._handle.dropMembership(multicastAddress, interfaceAddress);
+  if (this._handle.dropMembership(multicastAddress, interfaceAddress)) {
+    throw new errnoException(errno, 'dropMembership');
+  }
 };