diff --git a/integration_tests/test_coverage.py b/integration_tests/test_coverage.py
index b4dca47..37217aa 100644
--- a/integration_tests/test_coverage.py
+++ b/integration_tests/test_coverage.py
@@ -51,6 +51,9 @@ def _read_test_config():
     assert "exclude_path" in coverage_config
     assert "crate_features" in coverage_config
 
+    assert ' ' not in coverage_config["crate_features"], \
+        "spaces are not allowed in crate_features value"
+
     return coverage_config