diff --git a/plugins/inventory/nb_inventory.py b/plugins/inventory/nb_inventory.py
index da9f5ed72..66a21ad96 100644
--- a/plugins/inventory/nb_inventory.py
+++ b/plugins/inventory/nb_inventory.py
@@ -867,7 +867,11 @@ def extract_interfaces(self, host):
 
     def extract_custom_fields(self, host):
         try:
-            return host["custom_fields"]
+            return {
+                key: value
+                for key, value in host["custom_fields"].items()
+                if value is not None
+            }
         except Exception:
             return
 
diff --git a/tests/unit/inventory/test_data/extract_custom_fields/data.json b/tests/unit/inventory/test_data/extract_custom_fields/data.json
new file mode 100644
index 000000000..cb63c576e
--- /dev/null
+++ b/tests/unit/inventory/test_data/extract_custom_fields/data.json
@@ -0,0 +1,21 @@
+[
+    {
+        "custom_fields": {
+            "a_text_value": "value1",
+            "a_bool_value": false
+        },
+        "expected": {
+            "a_text_value": "value1",
+            "a_bool_value": false
+        }
+    },
+    {
+        "custom_fields": {
+            "an_unset_value": null,
+            "a_set_value": false
+        },
+        "expected": {
+            "a_set_value": false
+        }
+    }
+]
diff --git a/tests/unit/inventory/test_nb_inventory.py b/tests/unit/inventory/test_nb_inventory.py
index 9adfc3e3e..998c5a737 100644
--- a/tests/unit/inventory/test_nb_inventory.py
+++ b/tests/unit/inventory/test_nb_inventory.py
@@ -246,3 +246,14 @@ def test_new_token(inventory_fixture, templar_fixture):
 
     assert "Authorization" in inventory_fixture.headers
     assert inventory_fixture.headers["Authorization"] == "Foo bar"
+
+
+@pytest.mark.parametrize(
+    "custom_fields, expected", load_relative_test_data("extract_custom_fields")
+)
+def test_extract_custom_fields(inventory_fixture, custom_fields, expected):
+    extracted_custom_fields = inventory_fixture.extract_custom_fields(
+        {"custom_fields": custom_fields}
+    )
+
+    assert extracted_custom_fields == expected