diff --git a/src/bitcoinrpc.cpp b/src/bitcoinrpc.cpp
index fa392363..64154bf1 100644
--- a/src/bitcoinrpc.cpp
+++ b/src/bitcoinrpc.cpp
@@ -816,7 +816,7 @@ void ThreadRPCServer2(void* parg)
     }
     catch(boost::system::system_error &e)
     {
-        strerr = strprintf(_("An error occurred while setting up the RPC port %i for listening on IPv4: %s"), endpoint.port(), e.what());
+        strerr = strprintf(_("An error occurred while setting up the RPC port %u for listening on IPv4: %s"), endpoint.port(), e.what());
     }
 
     if (!fListening) {
diff --git a/src/main.h b/src/main.h
index e61cbdd4..a233f00f 100644
--- a/src/main.h
+++ b/src/main.h
@@ -158,7 +158,7 @@ public:
         if (IsNull())
             return "null";
         else
-            return strprintf("(nFile=%d, nBlockPos=%d, nTxPos=%d)", nFile, nBlockPos, nTxPos);
+            return strprintf("(nFile=%u, nBlockPos=%u, nTxPos=%u)", nFile, nBlockPos, nTxPos);
     }
 
     void print() const
@@ -214,7 +214,7 @@ public:
 
     std::string ToString() const
     {
-        return strprintf("COutPoint(%s, %d)", hash.ToString().substr(0,10).c_str(), n);
+        return strprintf("COutPoint(%s, %u)", hash.ToString().substr(0,10).c_str(), n);
     }
 
     void print() const
@@ -632,7 +632,7 @@ public:
     std::string ToString() const
     {
         std::string str;
-        str += strprintf("CTransaction(hash=%s, ver=%d, vin.size=%d, vout.size=%d, nLockTime=%d)\n",
+        str += strprintf("CTransaction(hash=%s, ver=%d, vin.size=%u, vout.size=%u, nLockTime=%u)\n",
             GetHash().ToString().substr(0,10).c_str(),
             nVersion,
             vin.size(),
@@ -1174,7 +1174,7 @@ public:
 
     std::string ToString() const
     {
-        return strprintf("CBlockIndex(pprev=%08x, pnext=%08x, nFile=%d, nBlockPos=%-6d nHeight=%d, merkle=%s, hashBlock=%s)",
+        return strprintf("CBlockIndex(pprev=%08x, pnext=%08x, nFile=%u, nBlockPos=%-6u nHeight=%d, merkle=%s, hashBlock=%s)",
             pprev, pnext, nFile, nBlockPos, nHeight,
             hashMerkleRoot.ToString().substr(0,10).c_str(),
             GetBlockHash().ToString().substr(0,20).c_str());
diff --git a/src/net.cpp b/src/net.cpp
index c0693306..651f4a97 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1025,7 +1025,7 @@ void ThreadMapPort2(void* parg)
 {
     printf("ThreadMapPort started\n");
 
-    std::string port = strprintf("%d", GetListenPort());
+    std::string port = strprintf("%u", GetListenPort());
     const char * multicastif = 0;
     const char * minissdpdpath = 0;
     struct UPNPDev * devlist = 0;
diff --git a/src/netbase.cpp b/src/netbase.cpp
index b66c3666..4face7a1 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -599,7 +599,7 @@ CNetAddr::CNetAddr(const std::string &strIp, bool fAllowLookup)
         *this = vIP[0];
 }
 
-int CNetAddr::GetByte(int n) const
+unsigned int CNetAddr::GetByte(int n) const
 {
     return ip[15-n];
 }
@@ -1135,7 +1135,7 @@ std::vector<unsigned char> CService::GetKey() const
 
 std::string CService::ToStringPort() const
 {
-    return strprintf("%i", port);
+    return strprintf("%u", port);
 }
 
 std::string CService::ToStringIPPort() const
diff --git a/src/netbase.h b/src/netbase.h
index 07ca12cb..560e2182 100644
--- a/src/netbase.h
+++ b/src/netbase.h
@@ -66,7 +66,7 @@ class CNetAddr
         enum Network GetNetwork() const;
         std::string ToString() const;
         std::string ToStringIP() const;
-        int GetByte(int n) const;
+        unsigned int GetByte(int n) const;
         uint64 GetHash() const;
         bool GetInAddr(struct in_addr* pipv4Addr) const;
         std::vector<unsigned char> GetGroup() const;