diff --git a/src/base/system.c b/src/base/system.c
index 58d39035c..ccb28d970 100644
--- a/src/base/system.c
+++ b/src/base/system.c
@@ -2377,6 +2377,8 @@ int os_compare_version(int major, int minor)
 		return 0;
 	else
 		return -1;
+#else
+	return 0; // unimplemented
 #endif
 }
 
diff --git a/src/engine/external/zlib/gzguts.h b/src/engine/external/zlib/gzguts.h
index d87659d03..896394760 100644
--- a/src/engine/external/zlib/gzguts.h
+++ b/src/engine/external/zlib/gzguts.h
@@ -19,6 +19,7 @@
 #endif
 
 #include <stdio.h>
+#include <unistd.h>
 #include "zlib.h"
 #ifdef STDC
 #  include <string.h>
diff --git a/src/engine/shared/network_conn.cpp b/src/engine/shared/network_conn.cpp
index b5a5e2e3f..690a1d32e 100644
--- a/src/engine/shared/network_conn.cpp
+++ b/src/engine/shared/network_conn.cpp
@@ -203,13 +203,13 @@ int CNetConnection::Feed(CNetPacketConstruct *pPacket, NETADDR *pAddr, SECURITY_
 	if (State() != NET_CONNSTATE_OFFLINE && m_SecurityToken != NET_SECURITY_TOKEN_UNKNOWN && m_SecurityToken != NET_SECURITY_TOKEN_UNSUPPORTED)
 	{
 		// supposed to have a valid token in this packet, check it
-		if (pPacket->m_DataSize < sizeof(m_SecurityToken))
+		if (pPacket->m_DataSize < (int)sizeof(m_SecurityToken))
 			return 0;
 		pPacket->m_DataSize -= sizeof(m_SecurityToken);
-		if (m_SecurityToken != *(SECURITY_TOKEN*)&pPacket->m_aChunkData[pPacket->m_DataSize])
+		if (m_SecurityToken != (SECURITY_TOKEN)(pPacket->m_aChunkData[pPacket->m_DataSize]))
 		{
 			if(g_Config.m_Debug)
-				dbg_msg("security", "token mismatch, expected %d got %d", m_SecurityToken, *(SECURITY_TOKEN*)&pPacket->m_aChunkData[pPacket->m_DataSize]);
+				dbg_msg("security", "token mismatch, expected %d got %d", m_SecurityToken, (SECURITY_TOKEN)(pPacket->m_aChunkData[pPacket->m_DataSize]));
 			return 0;
 		}
 	}
@@ -278,7 +278,7 @@ int CNetConnection::Feed(CNetPacketConstruct *pPacket, NETADDR *pAddr, SECURITY_
 					m_LastRecvTime = Now;
 					m_LastUpdateTime = Now;
 					if (m_SecurityToken == NET_SECURITY_TOKEN_UNKNOWN
-						&& pPacket->m_DataSize >= 1 + sizeof(SECURITY_TOKEN_MAGIC) + sizeof(m_SecurityToken)
+						&& pPacket->m_DataSize >= (int)(1 + sizeof(SECURITY_TOKEN_MAGIC) + sizeof(m_SecurityToken))
 						&& !mem_comp(&pPacket->m_aChunkData[1], SECURITY_TOKEN_MAGIC, sizeof(SECURITY_TOKEN_MAGIC)))
 					{
 						m_SecurityToken = SecurityToken;
@@ -302,10 +302,10 @@ int CNetConnection::Feed(CNetPacketConstruct *pPacket, NETADDR *pAddr, SECURITY_
 				if(CtrlMsg == NET_CTRLMSG_CONNECTACCEPT)
 				{
 					if (m_SecurityToken == NET_SECURITY_TOKEN_UNKNOWN
-						&& pPacket->m_DataSize >= 1 + sizeof(SECURITY_TOKEN_MAGIC) + sizeof(m_SecurityToken)
+						&& pPacket->m_DataSize >= (int)(1 + sizeof(SECURITY_TOKEN_MAGIC) + sizeof(m_SecurityToken))
 						&& !mem_comp(&pPacket->m_aChunkData[1], SECURITY_TOKEN_MAGIC, sizeof(SECURITY_TOKEN_MAGIC)))
 					{
-						m_SecurityToken = *(SECURITY_TOKEN*)(&pPacket->m_aChunkData[1 + sizeof(SECURITY_TOKEN_MAGIC)]);
+						m_SecurityToken = (SECURITY_TOKEN)*(&pPacket->m_aChunkData[1 + sizeof(SECURITY_TOKEN_MAGIC)]);
 						if(g_Config.m_Debug)
 							dbg_msg("security", "got token %d", m_SecurityToken);
 					}
diff --git a/src/engine/shared/network_server.cpp b/src/engine/shared/network_server.cpp
index 082e9d362..466729c86 100644
--- a/src/engine/shared/network_server.cpp
+++ b/src/engine/shared/network_server.cpp
@@ -201,7 +201,7 @@ int CNetServer::Recv(CNetChunk *pChunk)
 									md5_append(&md5, (unsigned char*)&Addr, sizeof(Addr));
 									md5_append(&md5, (unsigned char*)&timestamp, sizeof(timestamp));
 									md5_finish(&md5, digest);
-									securityToken = *(SECURITY_TOKEN*)digest;
+									securityToken = (SECURITY_TOKEN)*digest;
 									timestamp++;
 								}
 								while (securityToken == NET_SECURITY_TOKEN_UNKNOWN || securityToken == NET_SECURITY_TOKEN_UNSUPPORTED);