diff --git a/lib/config/definitions.js b/lib/config/definitions.js
index f1252a30cfd587864fad6d3e84ef2ffa6747dc01..e3e5245e00484e8651751acf439906e20f71fccb 100644
--- a/lib/config/definitions.js
+++ b/lib/config/definitions.js
@@ -1134,6 +1134,7 @@ const options = [
       enabled: false,
       commitMessageTopic: 'Rust crate {{depName}}',
       managerBranchPrefix: 'rust-',
+      fileMatch: ['(^|/)Cargo.toml$'],
     },
     mergeable: true,
   },