diff --git a/src/main.h b/src/main.h
index acea707ea..a0ba6e913 100644
--- a/src/main.h
+++ b/src/main.h
@@ -632,6 +632,9 @@ bool ConnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, C
 // Add this block to the block index, and if necessary, switch the active block chain to this
 bool AddToBlockIndex(CBlock& block, CValidationState& state, const CDiskBlockPos& pos);
 
+// Get the block at which AuxPoW is enabled for this network
+int GetAuxPowStartBlock();
+
 // Context-independent validity checks
 bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, int nHeight, bool fCheckPOW = true);
 bool CheckBlock(const CBlock& block, CValidationState& state, int nHeight, bool fCheckPOW = true, bool fCheckMerkleRoot = true);
diff --git a/src/rpcmining.cpp b/src/rpcmining.cpp
index 55b51a556..563c24cfc 100644
--- a/src/rpcmining.cpp
+++ b/src/rpcmining.cpp
@@ -657,10 +657,15 @@ Value getworkaux(const Array& params, bool fHelp)
             );
 
     if (vNodes.empty())
-        throw JSONRPCError(-9, "Dogecoin is not connected!");
+        throw JSONRPCError(RPC_CLIENT_NOT_CONNECTED, "Dogecoin is not connected!");
 
     if (IsInitialBlockDownload())
-        throw JSONRPCError(-10, "Dogecoin is downloading blocks...");
+        throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, "Dogecoin is downloading blocks...");
+    
+    // We use height plus one because we're testing the next block
+    if ((chainActive.Tip()->nHeight+1) < GetAuxPowStartBlock()) {
+        throw JSONRPCError(RPC_METHOD_NOT_FOUND, "getworkaux method is not available until switch-over block.");
+    }
 
     static map<uint256, pair<CBlock*, unsigned int> > mapNewBlock;
     static vector<CBlockTemplate*> vNewBlockTemplate;
@@ -818,10 +823,15 @@ Value getauxblock(const Array& params, bool fHelp)
             "the aux proof of work and returns true if it was successful.");
 
     if (vNodes.empty())
-        throw JSONRPCError(-9, "Dogecoin is not connected!");
+        throw JSONRPCError(RPC_CLIENT_NOT_CONNECTED, "Dogecoin is not connected!");
 
     if (IsInitialBlockDownload())
-        throw JSONRPCError(-10, "Dogecoin is downloading blocks...");
+        throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, "Dogecoin is downloading blocks...");
+    
+    // We use height plus one because we're testing the next block
+    if ((chainActive.Tip()->nHeight+1) < GetAuxPowStartBlock()) {
+        throw JSONRPCError(RPC_METHOD_NOT_FOUND, "getauxblock method is not available until switch-over block.");
+    }
 
     static map<uint256, CBlock*> mapNewBlock;
     static vector<CBlockTemplate*> vNewBlockTemplate;