diff --git a/toolkit/components/url-classifier/HashStore.cpp b/toolkit/components/url-classifier/HashStore.cpp
index d39c1232b179..9dea1d2bcb05 100644
--- a/toolkit/components/url-classifier/HashStore.cpp
+++ b/toolkit/components/url-classifier/HashStore.cpp
@@ -333,7 +333,10 @@ nsresult HashStore::Open(uint32_t aVersion) {
   NS_ENSURE_SUCCESS(rv, rv);
 
   rv = ReadHeader();
-  NS_ENSURE_SUCCESS(rv, rv);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    LOG(("Failed to read header for %s", mTableName.get()));
+    return NS_ERROR_FILE_CORRUPTED;
+  }
 
   rv = SanityCheck(aVersion);
   NS_ENSURE_SUCCESS(rv, rv);
diff --git a/toolkit/components/url-classifier/LookupCache.cpp b/toolkit/components/url-classifier/LookupCache.cpp
index 6ff62109f254..7e72353e11dd 100644
--- a/toolkit/components/url-classifier/LookupCache.cpp
+++ b/toolkit/components/url-classifier/LookupCache.cpp
@@ -684,7 +684,8 @@ nsresult LookupCache::LoadFromFile(nsCOMPtr<nsIFile>& aFile) {
   Header header;
   rv = ReadValue(in, header);
   if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
+    LOG(("Failed to read header for %s", mTableName.get()));
+    return NS_ERROR_FILE_CORRUPTED;
   }
 
   rv = SanityCheck(header);