diff --git a/libclamav/matcher-ac.h b/libclamav/matcher-ac.h
index b2740ddb3..8370aec95 100644
--- a/libclamav/matcher-ac.h
+++ b/libclamav/matcher-ac.h
@@ -41,7 +41,7 @@ struct cli_ac_data {
     uint32_t *offset;
     uint32_t macro_lastmatch[32];
     /** Hashset for versioninfo matching */
-    struct cli_hashset *vinfo;
+    const struct cli_hashset *vinfo;
 };
 
 struct cli_ac_special {