diff --git a/neo/framework/Common.cpp b/neo/framework/Common.cpp
index ce5bdaba..dbe8af58 100644
--- a/neo/framework/Common.cpp
+++ b/neo/framework/Common.cpp
@@ -1929,3 +1929,16 @@ CONSOLE_COMMAND( testSIMD, "test SIMD code", NULL )
 {
 	idSIMD::Test_f( args );
 }
+
+// RB begin
+CONSOLE_COMMAND( testFormattingSizes, "test printf format security", 0 )
+{
+#ifdef _MSC_VER
+	common->Printf( " sizeof( int32 ): %Iu bytes\n", sizeof( int32 ) );
+	common->Printf( " sizeof( int64 ): %Iu bytes\n", sizeof( int64 ) );
+#else
+	common->Printf( " sizeof( int32 ): %zu bytes\n", sizeof( int32 ) );
+	common->Printf( " sizeof( int64 ): %zu bytes\n", sizeof( int64 ) );
+#endif
+}
+// RB end
\ No newline at end of file
diff --git a/neo/framework/File.cpp b/neo/framework/File.cpp
index f4add176..7bb61ce8 100644
--- a/neo/framework/File.cpp
+++ b/neo/framework/File.cpp
@@ -844,7 +844,11 @@ int idFile_Memory::Write( const void* buffer, int len )
 	{
 		if( maxSize != 0 )
 		{
-			common->Error( "idFile_Memory::Write: exceeded maximum size %lu", maxSize );
+#ifdef _MSC_VER
+			common->Error( "idFile_Memory::Write: exceeded maximum size %Iu", maxSize );
+#else
+			common->Error( "idFile_Memory::Write: exceeded maximum size %zu", maxSize );
+#endif
 			return 0;
 		}
 		int extra = granularity * ( 1 + alloc / granularity );
@@ -930,7 +934,13 @@ void idFile_Memory::PreAllocate( size_t len )
 	{
 		if( maxSize != 0 )
 		{
-			idLib::Error( "idFile_Memory::SetLength: exceeded maximum size %lu", maxSize );
+// RB begin
+#ifdef _MSC_VER
+			idLib::Error( "idFile_Memory::SetLength: exceeded maximum size %Iu", maxSize );
+#else
+			idLib::Error( "idFile_Memory::SetLength: exceeded maximum size %zu", maxSize );
+#endif
+// RB end
 		}
 		char* newPtr = ( char* )Mem_Alloc( len, TAG_IDFILE );
 		if( allocated > 0 )
@@ -1116,7 +1126,13 @@ void idFile_Memory::TruncateData( size_t len )
 {
 	if( len > allocated )
 	{
-		idLib::Error( "idFile_Memory::TruncateData: len (%lu) exceeded allocated size (%lu)", len, allocated );
+// RB begin
+#ifdef _MSV_VER
+		idLib::Error( "idFile_Memory::TruncateData: len (%Iu) exceeded allocated size (%Iu)", len, allocated );
+#else
+		idLib::Error( "idFile_Memory::TruncateData: len (%zu) exceeded allocated size (%zu)", len, allocated );
+#endif
+// RB end
 	}
 	else
 	{
diff --git a/neo/framework/Zip.cpp b/neo/framework/Zip.cpp
index 7f29d3b0..4246d520 100644
--- a/neo/framework/Zip.cpp
+++ b/neo/framework/Zip.cpp
@@ -504,7 +504,13 @@ bool idZipBuilder::CreateZipFileFromFiles( const idList< idFile_Memory* >& srcFi
 					errcode = zipWriteInFileInZip( zf, buffer.Ptr(), ( unsigned int )bytesRead );
 					if( errcode != ZIP_OK )
 					{
-						idLib::Warning( "Error writing to zipfile (%lu bytes)!", bytesRead );
+// RB begin
+#ifdef _MSC_VER
+						idLib::Warning( "Error writing to zipfile (%Iu bytes)!", bytesRead );
+#else
+						idLib::Warning( "Error writing to zipfile (%zu bytes)!", bytesRead );
+#endif
+// RB end
 						continue;
 					}
 				}
@@ -612,7 +618,13 @@ bool idZipBuilder::AddFile( zipFile zf, idFile_Memory* src, bool deleteFile )
 				errcode = zipWriteInFileInZip( zf, buffer.Ptr(), ( unsigned int )bytesRead );
 				if( errcode != ZIP_OK )
 				{
-					idLib::Warning( "Error writing to zipfile (%lu bytes)!", bytesRead );
+// RB begin
+#ifdef _MSC_VER
+					idLib::Warning( "Error writing to zipfile (%Iu bytes)!", bytesRead );
+#else
+					idLib::Warning( "Error writing to zipfile (%zu bytes)!", bytesRead );
+#endif
+// RB end
 					continue;
 				}
 			}
diff --git a/neo/libs/zlib/trees.c b/neo/libs/zlib/trees.c
index 8c32b214..b9c72b4c 100644
--- a/neo/libs/zlib/trees.c
+++ b/neo/libs/zlib/trees.c
@@ -940,11 +940,17 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
         /* Determine the best encoding. Compute the block lengths in bytes. */
         opt_lenb = (s->opt_len+3+7)>>3;
         static_lenb = (s->static_len+3+7)>>3;
-
-        Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
+// RB begin
+#ifdef _MSC_VER
+		Tracev((stderr, "\nopt %Iu(%Iu) stat %Iu(%Iu) stored %Iu lit %u ",
                 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
                 s->last_lit));
-
+#else
+        Tracev((stderr, "\nopt %zu(%zu) stat %zu(%zu) stored %zu lit %u ",
+                opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
+                s->last_lit));
+#endif
+// RB end
         if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
 
     } else {
@@ -997,8 +1003,16 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
         s->compressed_len += 7;  /* align on byte boundary */
 #endif
     }
-    Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
+
+// RB begin
+#ifdef _MSC_VER
+    Tracev((stderr,"\ncomprlen %Iu(%Iu) ", s->compressed_len>>3,
            s->compressed_len-7*last));
+#else
+	Tracev((stderr,"\ncomprlen %zu(%zu) ", s->compressed_len>>3,
+           s->compressed_len-7*last));
+#endif
+// RB end
 }
 
 /* ===========================================================================