--- src/lib/RagTime5StructManager.cxx
+++ src/lib/RagTime5StructManager.cxx
@@ -307,7 +307,7 @@
     fSz-=4;
   long debDataPos=input->tell();
   long endDataPos=debDataPos+fSz;
-  switch (type) {
+  switch ((unsigned long) type) {
   case 0x360c0:
   case 0x368c0:
     if (fSz!=1) {