diff --git a/homeassistant/components/airgradient/quality_scale.yaml b/homeassistant/components/airgradient/quality_scale.yaml
index 71132fdb47a..43816401cdb 100644
--- a/homeassistant/components/airgradient/quality_scale.yaml
+++ b/homeassistant/components/airgradient/quality_scale.yaml
@@ -7,9 +7,7 @@ rules:
   appropriate-polling: done
   brands: done
   common-modules: done
-  config-flow-test-coverage:
-    status: todo
-    comment: Missing zeroconf duplicate entry test.
+  config-flow-test-coverage: done
   config-flow: done
   dependency-transparency: done
   docs-actions:
diff --git a/tests/components/airgradient/test_config_flow.py b/tests/components/airgradient/test_config_flow.py
index 73dbd17a213..8927947c40e 100644
--- a/tests/components/airgradient/test_config_flow.py
+++ b/tests/components/airgradient/test_config_flow.py
@@ -255,6 +255,20 @@ async def test_zeroconf_flow_abort_old_firmware(hass: HomeAssistant) -> None:
     assert result["reason"] == "invalid_version"
 
 
+async def test_zeroconf_flow_abort_duplicate(
+    hass: HomeAssistant, mock_config_entry: MockConfigEntry
+) -> None:
+    """Test zeroconf flow aborts with duplicate."""
+    mock_config_entry.add_to_hass(hass)
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={"source": SOURCE_ZEROCONF},
+        data=ZEROCONF_DISCOVERY,
+    )
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "already_configured"
+
+
 async def test_user_flow_works_discovery(
     hass: HomeAssistant,
     mock_new_airgradient_client: AsyncMock,