diff --git a/src/modb_groups.c b/src/modb_groups.c
index 6713b5d..c8858ae 100644
--- a/src/modb_groups.c
+++ b/src/modb_groups.c
@@ -105,6 +105,8 @@ int doGroupsQuery(stored_conn *sconn, modb_ref *modb, where_builder *wb,
   // Zero row result
   if (qry_ret == 0) {
     freeColumns(col_data, n_cols);
+    *groups = 0;
+    *n_groups = 0;
     return 0;
   }
 
diff --git a/src/modb_metadata.c b/src/modb_metadata.c
index 7e89852..6c75476 100644
--- a/src/modb_metadata.c
+++ b/src/modb_metadata.c
@@ -112,6 +112,8 @@ int doMetadataListQuery(stored_conn *sconn, modb_ref *modb, where_builder *wb,
   // Zero row result
   if (qry_ret == 0) {
     freeColumns(col_data, n_cols);
+    *metadata_list = 0;
+    *n_metadatas = 0;
     return 0;
   }
 
diff --git a/src/modb_objects.c b/src/modb_objects.c
index d520cea..39fc3cf 100644
--- a/src/modb_objects.c
+++ b/src/modb_objects.c
@@ -93,6 +93,8 @@ int doObjectsQuery(stored_conn *sconn, modb_ref *modb, where_builder *wb,
   // Zero row result
   if (qry_ret == 0) {
     freeColumns(col_data, n_cols);
+    *objects = 0;
+    *n_objects = 0;
     return 0;
   }
 
diff --git a/src/modb_users.c b/src/modb_users.c
index 68ed239..4f7280b 100644
--- a/src/modb_users.c
+++ b/src/modb_users.c
@@ -111,6 +111,8 @@ int doUsersQuery(stored_conn *sconn, modb_ref *modb, where_builder *wb,
   // Zero row result
   if (qry_ret == 0) {
     freeColumns(col_data, n_cols);
+    *users = 0;
+    *n_users = 0;
     return 0;
   }