diff --git a/lib/DB.zig b/lib/DB.zig
index d27c97c..53d3413 100644
--- a/lib/DB.zig
+++ b/lib/DB.zig
@@ -400,14 +400,20 @@ fn additionalGids(
     try compress.appendUvarint(&blob, 0);
 
     var scratch = try allocator.alloc(u32, 256);
-    defer allocator.free(scratch);
+    var scratch_allocated: bool = true;
+    defer if (scratch_allocated) allocator.free(scratch);
     for (corpus.user2groups) |usergroups, user_idx| {
         if (usergroups.len == 0) {
             idx2offset[user_idx] = 0;
             continue;
         }
         idx2offset[user_idx] = blob.items.len;
-        scratch = try allocator.realloc(scratch, usergroups.len);
+        if (scratch.len < usergroups.len) {
+            allocator.free(scratch);
+            scratch_allocated = false;
+            scratch = try allocator.alloc(u32, usergroups.len);
+            scratch_allocated = true;
+        }
         scratch.len = usergroups.len;
         const corpusGids = corpus.groups.items(.gid);
         for (usergroups) |group_idx, i|