diff --git a/lib/configuration/llm_enumerator.rb b/lib/configuration/llm_enumerator.rb
index 30a8b694..1209001d 100644
--- a/lib/configuration/llm_enumerator.rb
+++ b/lib/configuration/llm_enumerator.rb
@@ -38,7 +38,7 @@ module DiscourseAi
           rval[model_id] << { type: :ai_embeddings_semantic_search }
         end
 
-        if SiteSetting.ai_spam_detection_enabled
+        if SiteSetting.ai_spam_detection_enabled && AiModerationSetting.spam.present?
           model_id = AiModerationSetting.spam[:llm_model_id]
           rval[model_id] << { type: :ai_spam }
         end
diff --git a/spec/configuration/llm_enumerator_spec.rb b/spec/configuration/llm_enumerator_spec.rb
new file mode 100644
index 00000000..771dff35
--- /dev/null
+++ b/spec/configuration/llm_enumerator_spec.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+RSpec.describe DiscourseAi::Configuration::LlmEnumerator do
+  fab!(:fake_model)
+
+  describe "#global_usage" do
+    before do
+      SiteSetting.ai_helper_model = "custom:#{fake_model.id}"
+      SiteSetting.ai_helper_enabled = true
+    end
+
+    it "returns a hash of Llm models in use globally" do
+      expect(described_class.global_usage).to eq(fake_model.id => [{ type: :ai_helper }])
+    end
+
+    it "doesn't error on spam when spam detection is enabled but moderation setting is missing" do
+      SiteSetting.ai_spam_detection_enabled = true
+      expect { described_class.global_usage }.not_to raise_error
+    end
+  end
+end