diff --git a/.changeset/brown-ducks-admire.md b/.changeset/brown-ducks-admire.md
new file mode 100644
index 0000000000..a897ebf8d1
--- /dev/null
+++ b/.changeset/brown-ducks-admire.md
@@ -0,0 +1,5 @@
+---
+'@core/sync-service': patch
+---
+
+fix: wrong return value caused metric sending to fail sometimes
diff --git a/packages/sync-service/lib/electric/shapes/consumer_registry.ex b/packages/sync-service/lib/electric/shapes/consumer_registry.ex
index 16dd2ed082..62b1ee56a2 100644
--- a/packages/sync-service/lib/electric/shapes/consumer_registry.ex
+++ b/packages/sync-service/lib/electric/shapes/consumer_registry.ex
@@ -44,7 +44,10 @@ defmodule Electric.Shapes.ConsumerRegistry do
 
   @spec active_consumer_count(stack_id()) :: non_neg_integer()
   def active_consumer_count(stack_id) when is_binary(stack_id) do
-    :ets.info(ets_name(stack_id), :size)
+    case :ets.info(ets_name(stack_id), :size) do
+      :undefined -> 0
+      size -> size
+    end
   rescue
     ArgumentError -> 0
   end