diff --git a/app_runner/src/app_runner/specs/config_interpolation.py b/app_runner/src/app_runner/specs/config_interpolation.py
index 084ce821..6f0de48d 100644
--- a/app_runner/src/app_runner/specs/config_interpolation.py
+++ b/app_runner/src/app_runner/specs/config_interpolation.py
@@ -20,7 +20,7 @@ class VariablesApp(BaseModel):
 
     @field_validator("name", mode="before")
     def validate_safe_name(cls, value: str) -> str:
-        characters = re.compile(r"^[a-zA-Z0-9_-]+$")
+        characters = re.compile(r"[^a-zA-Z0-9_-]+")
         return characters.sub("_", value)