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);