diff --git a/common/rdr/FileInStream.cxx b/common/rdr/FileInStream.cxx
index 6d23aa2..8d5c22e 100644
--- a/common/rdr/FileInStream.cxx
+++ b/common/rdr/FileInStream.cxx
@@ -58,7 +58,7 @@
 
 int FileInStream::overrun(int itemSize, int nItems, bool wait)
 {
-  if (itemSize > sizeof(b))
+  if (itemSize > (int)sizeof(b))
     throw Exception("FileInStream overrun: max itemSize exceeded");
 
   if (end - ptr != 0)
diff --git a/common/rdr/RandomStream.cxx b/common/rdr/RandomStream.cxx
index 7056c2c..3fde18d 100644
--- a/common/rdr/RandomStream.cxx
+++ b/common/rdr/RandomStream.cxx
@@ -44,7 +44,7 @@
 #ifdef RFB_HAVE_WINCRYPT
   provider = 0;
   if (!CryptAcquireContext(&provider, 0, 0, PROV_RSA_FULL, 0)) {
-    if (GetLastError() == NTE_BAD_KEYSET) {
+    if (GetLastError() == (DWORD)NTE_BAD_KEYSET) {
       if (!CryptAcquireContext(&provider, 0, 0, PROV_RSA_FULL, CRYPT_NEWKEYSET)) {
         fprintf(stderr, "RandomStream: unable to create keyset\n");
         provider = 0;
diff --git a/common/rdr/TLSInStream.cxx b/common/rdr/TLSInStream.cxx
index 4d2c9ec..21b6056 100644
--- a/common/rdr/TLSInStream.cxx
+++ b/common/rdr/TLSInStream.cxx
@@ -44,7 +44,7 @@
       return -1;
     }
 
-    if (in->getend() - in->getptr() < size)
+    if (in->getend() - in->getptr() < (ptrdiff_t)size)
       size = in->getend() - in->getptr();
   
     in->readBytes(data, size);
diff --git a/common/rfb/EncodeManager.cxx b/common/rfb/EncodeManager.cxx
index e632387..4e133d3 100644
--- a/common/rfb/EncodeManager.cxx
+++ b/common/rfb/EncodeManager.cxx
@@ -152,7 +152,7 @@
 
 void EncodeManager::logStats()
 {
-  int i, j;
+  size_t i, j;
 
   unsigned rects;
   unsigned long long pixels, bytes, equivalent;
@@ -603,7 +603,7 @@
   Encoder *encoder;
 
   struct RectInfo info;
-  int divisor, maxColours;
+  unsigned int divisor, maxColours;
 
   bool useRLE;
   EncoderType type;
diff --git a/common/rfb/TightEncoder.cxx b/common/rfb/TightEncoder.cxx
index ec19c2e..fe2470b 100644
--- a/common/rfb/TightEncoder.cxx
+++ b/common/rfb/TightEncoder.cxx
@@ -201,7 +201,7 @@
   }
 
   while (count) {
-    int iter_count;
+    unsigned int iter_count;
 
     iter_count = sizeof(rgb)/3;
     if (iter_count > count)
diff --git a/common/rfb/VNCServerST.cxx b/common/rfb/VNCServerST.cxx
index 51cb86c..199524e 100644
--- a/common/rfb/VNCServerST.cxx
+++ b/common/rfb/VNCServerST.cxx
@@ -544,7 +544,7 @@
   if (!deferPending)
     return true;
 
-  if (msSince(&deferStart) >= deferUpdateTime)
+  if (msSince(&deferStart) >= (unsigned)deferUpdateTime)
     return true;
 
   return false;
diff --git a/tests/conv.cxx b/tests/conv.cxx
index 2ee523a..840f18d 100644
--- a/tests/conv.cxx
+++ b/tests/conv.cxx
@@ -266,7 +266,7 @@
 static void doTests(const rfb::PixelFormat &dstpf,
                     const rfb::PixelFormat &srcpf)
 {
-  int i;
+  size_t i;
   char dstb[256], srcb[256];
 
   dstpf.print(dstb, sizeof(dstb));
diff --git a/tests/convperf.cxx b/tests/convperf.cxx
index c8381d5..e4a3fd5 100644
--- a/tests/convperf.cxx
+++ b/tests/convperf.cxx
@@ -100,7 +100,7 @@
 
 static void doTests(rfb::PixelFormat &dstpf, rfb::PixelFormat &srcpf)
 {
-  int i;
+  size_t i;
   char dstb[256], srcb[256];
 
   dstpf.print(dstb, sizeof(dstb));
@@ -118,19 +118,19 @@
 
 int main(int argc, char **argv)
 {
-  int bufsize;
+  size_t bufsize;
 
   time_t t;
   char datebuffer[256];
 
-  int i;
+  size_t i;
 
   bufsize = fbsize * fbsize * 4;
 
   fb1 = new rdr::U8[bufsize];
   fb2 = new rdr::U8[bufsize];
 
-  for (int i = 0;i < bufsize;i++) {
+  for (i = 0;i < bufsize;i++) {
     fb1[i] = rand();
     fb2[i] = rand();
   }
diff --git a/vncviewer/CConn.cxx b/vncviewer/CConn.cxx
index cf4f31b..5935c17 100644
--- a/vncviewer/CConn.cxx
+++ b/vncviewer/CConn.cxx
@@ -134,7 +134,7 @@
 {
   OptionsDialog::removeCallback(handleOptions);
 
-  for (int i = 0; i < sizeof(decoders)/sizeof(decoders[0]); i++)
+  for (size_t i = 0; i < sizeof(decoders)/sizeof(decoders[0]); i++)
     delete decoders[i];
 
   if (desktop)
diff --git a/vncviewer/cocoa.mm b/vncviewer/cocoa.mm
index 0992100..e51cba9 100644
--- a/vncviewer/cocoa.mm
+++ b/vncviewer/cocoa.mm
@@ -57,7 +57,7 @@
       if (CGGetActiveDisplayList(16, displays, &count) != kCGErrorSuccess)
         return 1;
 
-      if (count != Fl::screen_count())
+      if (count != (unsigned)Fl::screen_count())
         return 1;
 
 #ifdef HAVE_FLTK_FULLSCREEN_SCREENS
@@ -424,7 +424,7 @@
   NSEvent *nsevent;
 
   UInt16 key_code;
-  int i;
+  size_t i;
 
   NSString *chars;
   UInt32 modifiers;
diff --git a/vncviewer/parameters.cxx b/vncviewer/parameters.cxx
index 184af08..29a5397 100644
--- a/vncviewer/parameters.cxx
+++ b/vncviewer/parameters.cxx
@@ -202,7 +202,7 @@
 
     } else {
 
-      for (int j = 0; j < sizeof(replaceMap)/sizeof(replaceMap[0]); j++) {
+      for (size_t j = 0; j < sizeof(replaceMap)/sizeof(replaceMap[0]); j++) {
 
         if (val[i] == replaceMap[j].first) {
           dest[pos] = '\\';
@@ -242,7 +242,7 @@
     // Check for escape sequences
     if (val[i] == '\\') {
       
-      for (int j = 0; j < sizeof(replaceMap)/sizeof(replaceMap[0]); j++) {
+      for (size_t j = 0; j < sizeof(replaceMap)/sizeof(replaceMap[0]); j++) {
         if (val[i+1] == replaceMap[j].second) {
           dest[pos] = replaceMap[j].first;
           escapedCharacter = true;
@@ -413,7 +413,7 @@
 
   setKeyString("ServerName", servername, &hKey);
 
-  for (int i = 0; i < sizeof(parameterArray)/sizeof(VoidParameter*); i++) {
+  for (size_t i = 0; i < sizeof(parameterArray)/sizeof(VoidParameter*); i++) {
     if (dynamic_cast<StringParameter*>(parameterArray[i]) != NULL) {
       setKeyString(parameterArray[i]->getName(), *(StringParameter*)parameterArray[i], &hKey);
     } else if (dynamic_cast<IntParameter*>(parameterArray[i]) != NULL) {
@@ -459,7 +459,7 @@
   int intValue = 0;
   char stringValue[buffersize];
   
-  for (int i = 0; i < sizeof(parameterArray)/sizeof(VoidParameter*); i++) {
+  for (size_t i = 0; i < sizeof(parameterArray)/sizeof(VoidParameter*); i++) {
     if (dynamic_cast<StringParameter*>(parameterArray[i]) != NULL) {
       if (getKeyString(parameterArray[i]->getName(), stringValue, buffersize, &hKey))
         parameterArray[i]->setParam(stringValue);
@@ -523,7 +523,7 @@
   if (encodeValue(servername, encodingBuffer, buffersize))  
     fprintf(f, "ServerName=%s\n", encodingBuffer);
   
-  for (int i = 0; i < sizeof(parameterArray)/sizeof(VoidParameter*); i++) {
+  for (size_t i = 0; i < sizeof(parameterArray)/sizeof(VoidParameter*); i++) {
     if (dynamic_cast<StringParameter*>(parameterArray[i]) != NULL) {
       if (encodeValue(*(StringParameter*)parameterArray[i], encodingBuffer, buffersize))
         fprintf(f, "%s=%s\n", ((StringParameter*)parameterArray[i])->getName(), encodingBuffer);
@@ -635,7 +635,7 @@
     } else {
     
       // Find and set the correct parameter
-      for (int i = 0; i < sizeof(parameterArray)/sizeof(VoidParameter*); i++) {
+      for (size_t i = 0; i < sizeof(parameterArray)/sizeof(VoidParameter*); i++) {
 
         if (dynamic_cast<StringParameter*>(parameterArray[i]) != NULL) {
           if (strcasecmp(line, ((StringParameter*)parameterArray[i])->getName()) == 0) {
diff --git a/win/rfb_win32/CleanDesktop.cxx b/win/rfb_win32/CleanDesktop.cxx
index 52dc6bd..bad95f0 100644
--- a/win/rfb_win32/CleanDesktop.cxx
+++ b/win/rfb_win32/CleanDesktop.cxx
@@ -129,7 +129,7 @@
         vlog.error("failed to get desktop item count: %ld", hr);
         return false;
       }
-      for (unsigned int i=0; i<itemCount; i++) {
+      for (int i=0; i<itemCount; i++) {
         if (enableItem(i, false))
           restoreItems.insert(i);
       }
diff --git a/win/rfb_win32/TsSessions.cxx b/win/rfb_win32/TsSessions.cxx
index efe7564..a4fac2f 100644
--- a/win/rfb_win32/TsSessions.cxx
+++ b/win/rfb_win32/TsSessions.cxx
@@ -48,7 +48,7 @@
     id = 0;
     if (!_ProcessIdToSessionId.isValid())
       return;
-    if (processId == -1)
+    if (processId == (DWORD)-1)
       processId = GetCurrentProcessId();
     if (!(*_ProcessIdToSessionId)(GetCurrentProcessId(), &id))
       throw rdr::SystemException("ProcessIdToSessionId", GetLastError());
@@ -72,7 +72,7 @@
 #ifdef RFB_HAVE_WINSTATION_CONNECT
     if (!_WinStationConnect.isValid())
       throw rdr::Exception("WinSta APIs missing");
-    if (sessionId == -1)
+    if (sessionId == (DWORD)-1)
       sessionId = mySessionId.id;
 
     // Try to reconnect our session to the console
diff --git a/win/vncconfig/Connections.h b/win/vncconfig/Connections.h
index 209e4fd..6176f3d 100644
--- a/win/vncconfig/Connections.h
+++ b/win/vncconfig/Connections.h
@@ -117,11 +117,11 @@
         case IDC_HOSTS:
           {
             DWORD selected = SendMessage(GetDlgItem(handle, IDC_HOSTS), LB_GETCURSEL, 0, 0);
-            int count = SendMessage(GetDlgItem(handle, IDC_HOSTS), LB_GETCOUNT, 0, 0);
-            bool enable = selected != LB_ERR;
+            DWORD count = SendMessage(GetDlgItem(handle, IDC_HOSTS), LB_GETCOUNT, 0, 0);
+            bool enable = selected != (DWORD)LB_ERR;
             enableItem(IDC_HOST_REMOVE, enable);
             enableItem(IDC_HOST_UP, enable && (selected > 0));
-            enableItem(IDC_HOST_DOWN, enable && (selected < count-1));
+            enableItem(IDC_HOST_DOWN, enable && (selected+1 < count));
             enableItem(IDC_HOST_EDIT, enable);
             setChanged(isChanged());
           }