diff --git a/README.md b/README.md
index 4e27fb1..42402df 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ You can test models independently by mocking their dependencies (models, sources
   - [Main Features](#main-features)
 - [Documentation](#documentation)
   - [Anatomy of a test](#anatomy-of-a-test)
+  - [Running Tests](#running-tests)
   - [Available Macros](#available-macros)
   - [Test Examples](#test-examples)
   - [Different ways to build mock values](#different-ways-to-build-mock-values)
diff --git a/integration-tests/models/model_ephemeral.sql b/integration-tests/models/model_ephemeral.sql
new file mode 100644
index 0000000..ee2dbfd
--- /dev/null
+++ b/integration-tests/models/model_ephemeral.sql
@@ -0,0 +1,3 @@
+{{ config (materialized = 'incremental' ) }}
+
+select 1 as a, 'b' as b
\ No newline at end of file
diff --git a/integration-tests/models/model_references_ephemeral.sql b/integration-tests/models/model_references_ephemeral.sql
new file mode 100644
index 0000000..94f3f79
--- /dev/null
+++ b/integration-tests/models/model_references_ephemeral.sql
@@ -0,0 +1 @@
+select * from {{ dbt_unit_testing.ref('model_ephemeral') }} where a >= 1
diff --git a/integration-tests/tests/unit/model_references_ephemeral.sql b/integration-tests/tests/unit/model_references_ephemeral.sql
new file mode 100644
index 0000000..88d92a0
--- /dev/null
+++ b/integration-tests/tests/unit/model_references_ephemeral.sql
@@ -0,0 +1,16 @@
+{{
+    config(
+        tags=['unit-test', 'bigquery', 'snowflake', 'postgres']
+    )
+}}
+
+{% call dbt_unit_testing.test('model_ephemeral', 'sample test') %}
+  {% call dbt_unit_testing.mock_ref ('model_a') %}
+    select 0 as a, 'a' as b
+    UNION ALL
+    select 1 as a, 'b' as b
+  {% endcall %}
+  {% call dbt_unit_testing.expect() %}
+    select 1 as a, 'b' as b
+  {% endcall %}
+{% endcall %}
\ No newline at end of file
diff --git a/macros/utils.sql b/macros/utils.sql
index b16a83c..9629273 100644
--- a/macros/utils.sql
+++ b/macros/utils.sql
@@ -19,6 +19,7 @@
 {% endmacro %}
 
 {% macro extract_columns_difference(cl1, cl2) %}
+  !! WRONG !!
   {% set columns = cl1 | reject('in', cl2) | list %}
   {{ return(columns) }}
 {% endmacro %}