diff --git a/src/capabilities.rs b/src/capabilities.rs
--- a/src/capabilities.rs
+++ b/src/capabilities.rs
@@ -226,10 +226,7 @@ impl<'a> BrowserCapabilities for FirefoxCapabilities<'a> {
                                 if !data.contains_key("androidPackage")
                                     && self.version(Some(Path::new(binary))).is_err()
                                 {
-                                    return Err(WebDriverError::new(
-                                        ErrorStatus::InvalidArgument,
-                                        format!("{} is not a Firefox executable", &**key),
-                                    ));
+                                    warn!("{} is not a Mozilla Firefox executable", &**key);
                                 }
                             } else {
                                 return Err(WebDriverError::new(
-- 
2.40.1