diff --git a/src/lib/util/tagmap.h b/src/lib/util/tagmap.h
index 63855b30e07..23fd72a5369 100644
--- a/src/lib/util/tagmap.h
+++ b/src/lib/util/tagmap.h
@@ -114,8 +114,8 @@ public:
 	UINT32 hash(const char *string) const
 	{
 		UINT32 result = *string++;
-		for (char c = *string++; c != 0; c = *string++)
-			result = ((result << 5) | (result >> 27)) + c;
+		for (UINT8 c = *string++; c != 0; c = *string++)
+			result = (result*33) ^ c;
 		return result;
 	}