diff --git a/src/activemasternode.cpp b/src/activemasternode.cpp
index bed502b69..ee5931cec 100644
--- a/src/activemasternode.cpp
+++ b/src/activemasternode.cpp
@@ -49,6 +49,11 @@ void CActiveMasternode::ManageStatus()
                 LogPrintf("CActiveMasternode::ManageStatus() - not capable: %s\n", notCapableReason.c_str());
                 return;
             }
+        } else if(service.GetPort() == 9999) {
+            notCapableReason = "Invalid port: " + boost::lexical_cast<string>(service.GetPort()) + " - 9999 is only supported on mainnet.";
+            status = MASTERNODE_NOT_CAPABLE;
+            LogPrintf("CActiveMasternode::ManageStatus() - not capable: %s\n", notCapableReason.c_str());
+            return;
         }
 
         if(Params().NetworkID() == CChainParams::MAIN){
diff --git a/src/masternodeconfig.cpp b/src/masternodeconfig.cpp
index 4f32dd563..ca9fa798b 100644
--- a/src/masternodeconfig.cpp
+++ b/src/masternodeconfig.cpp
@@ -29,11 +29,18 @@ bool CMasternodeConfig::read(std::string& strErr) {
             return false;
         }
 
-/*        if(CService(ip).GetPort() != 19999 && CService(ip).GetPort() != 9999)  {
-            strErr = "Invalid port (must be 9999 for mainnet or 19999 for testnet) detected in masternode.conf: " + line;
+        if(Params().NetworkID() == CChainParams::MAIN){
+            if(CService(ip).GetPort() != 9999) {
+                strErr = "Invalid port detected in masternode.conf: " + line + " (must be 9999 for mainnet)";
+                streamConfig.close();
+                return false;
+            }
+        } else if(CService(ip).GetPort() == 9999) {
+            strErr = "Invalid port detected in masternode.conf: " + line + " (9999 must be only on mainnet)";
             streamConfig.close();
             return false;
-        }*/
+        }
+
 
         add(alias, ip, privKey, txHash, outputIndex);
     }
diff --git a/src/masternodeman.cpp b/src/masternodeman.cpp
index 8c3972cb3..3379f4c61 100644
--- a/src/masternodeman.cpp
+++ b/src/masternodeman.cpp
@@ -539,7 +539,7 @@ void CMasternodeMan::ProcessMessage(CNode* pfrom, std::string& strCommand, CData
 
         if(Params().NetworkID() == CChainParams::MAIN){
             if(addr.GetPort() != 9999) return;
-        }
+        } else if(addr.GetPort() == 9999) return;
 
         //search existing Masternode list, this is where we update existing Masternodes with new dsee broadcasts
         CMasternode* pmn = this->Find(vin);