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