diff --git a/lib/Makefile.vc6 b/lib/Makefile.vc6
index fcf97ce481..7db6063419 100644
--- a/lib/Makefile.vc6
+++ b/lib/Makefile.vc6
@@ -641,6 +641,9 @@ $(DIROBJ):
 {.\}.c{$(DIROBJ)\}.obj:
 	$(CC) $(CFLAGS) /Fo"$@"  $<
 
+{.\vtls\}.c{$(DIROBJ)\}.obj:
+	$(CC) $(CFLAGS) /Fo"$@"  $<
+
 debug-dll\libcurl.res \
 debug-dll-ssl-dll\libcurl.res \
 debug-dll-zlib-dll\libcurl.res \