diff --git a/keystore2/tests/legacy_blobs/keystore2_legacy_blob_tests.rs b/keystore2/tests/legacy_blobs/keystore2_legacy_blob_tests.rs
index 48275ae..32ecd03 100644
--- a/keystore2/tests/legacy_blobs/keystore2_legacy_blob_tests.rs
+++ b/keystore2/tests/legacy_blobs/keystore2_legacy_blob_tests.rs
@@ -85,7 +85,7 @@
         .expect("failed to execute pidof keystore2");
 
     let id = String::from_utf8(output.stdout).unwrap();
-    let id: String = id.chars().filter(|c| c.is_digit(10)).collect();
+    let id: String = id.chars().filter(|c| c.is_ascii_digit()).collect();
 
     let _status = std::process::Command::new("kill").arg("-9").arg(id).status().unwrap();