diff --git a/src/tox/tox_env/api.py b/src/tox/tox_env/api.py
index 52734cceb..05ef772aa 100644
--- a/src/tox/tox_env/api.py
+++ b/src/tox/tox_env/api.py
@@ -134,7 +134,7 @@ def pass_env_post_process(values: list[str]) -> list[str]:
             blank_values = [v for v in values if " " in v or "\t" in v]
             if blank_values:
                 raise Fail(
-                    f"pass_env/passenv variable can't have values containing blanks like {blank_values}; a comma is possibly missing"
+                    f"pass_env/passenv variable can't have values containing blanks like {blank_values}; a comma is possibly missing",
                 )
             values.extend(self._default_pass_env())
             return sorted({k: None for k in values}.keys())