diff -r d44748d98fe6 src/core/model/object-factory.cc
--- a/src/core/model/object-factory.cc	Mon Jun 20 00:00:15 2016 +0200
+++ b/src/core/model/object-factory.cc	Wed Jun 22 17:43:14 2016 -0700
@@ -139,8 +139,22 @@
   NS_ASSERT (lbracket != std::string::npos);
   NS_ASSERT (rbracket != std::string::npos);
   std::string tid = v.substr (0, lbracket);
+  factory.SetTypeId (tid);
   std::string parameters = v.substr (lbracket+1,rbracket-(lbracket+1));
-  factory.SetTypeId (tid);
+  bool invalidDelimiter = false;
+  if (parameters.find (',', 0) != std::string::npos)
+    {
+      invalidDelimiter = true;
+    }
+  if (parameters.find (':', 0) != std::string::npos)
+    {
+      invalidDelimiter = true;
+    }
+  if (invalidDelimiter == true)
+    {
+      is.setstate (std::ios_base::failbit);
+      return is;
+    }
   std::string::size_type cur;
   cur = 0;
   while (cur != parameters.size ())
diff -r d44748d98fe6 src/core/test/attribute-test-suite.cc
--- a/src/core/test/attribute-test-suite.cc	Mon Jun 20 00:00:15 2016 +0200
+++ b/src/core/test/attribute-test-suite.cc	Wed Jun 22 17:43:14 2016 -0700
@@ -823,17 +823,13 @@
   //
   // Try to set a UniformRandomVariable
   //
-  ok = p->SetAttributeFailSafe ("TestRandom", StringValue ("ns3::UniformRandomVariable[Min=0.,Max=1.]"));
+  ok = p->SetAttributeFailSafe ("TestRandom", StringValue ("ns3::UniformRandomVariable[Min=0.|Max=1.]"));
   NS_TEST_ASSERT_MSG_EQ (ok, true, "Could not SetAttributeFailSafe() a UniformRandomVariable");
 
   //
   // Try to set a <snicker> ConstantRandomVariable
   //
-  //  ok = p->SetAttributeFailSafe ("TestRandom", StringValue ("ns3::ConstantRandomVariable[Constant=10.0]"));
-  //ok = p->SetAttributeFailSafe ("TestRandom", StringValue ("ns3::UniformRandomVariable[Min=0.,Max=1.]"));
-
-  ok = p->SetAttributeFailSafe ("TestRandom", StringValue ("ns3::ConstantRandomVariable[Constant=1.0]"));
-
+  ok = p->SetAttributeFailSafe ("TestRandom", StringValue ("ns3::ConstantRandomVariable[Constant=10.0]"));
   NS_TEST_ASSERT_MSG_EQ (ok, true, "Could not SetAttributeFailSafe() a ConstantRandomVariable");
 }