diff --git a/security/manager/ssl/CertBlocklist.h b/security/manager/ssl/CertBlocklist.h
index bef8f2346e1d..931367de59c3 100644
--- a/security/manager/ssl/CertBlocklist.h
+++ b/security/manager/ssl/CertBlocklist.h
@@ -78,7 +78,7 @@ class CertBlocklist : public nsICertBlocklist {
   nsCOMPtr<nsIFile> mBackingFile;
 
  protected:
-  static void PreferenceChanged(const char* aPref, CertBlocklist* aBlocklist);
+  static void PreferenceChanged(const char* aPref, void* aBlocklist);
   static uint32_t sLastBlocklistUpdate;
   static uint32_t sLastKintoUpdate;
   static uint32_t sMaxStaleness;