diff --git a/accounts/keystore/key.go b/accounts/keystore/key.go
index 9b2ac14712..6a554d831c 100644
--- a/accounts/keystore/key.go
+++ b/accounts/keystore/key.go
@@ -205,7 +205,18 @@ func writeTemporaryKeyFile(file string, content []byte) (string, error) {
 		os.Remove(f.Name())
 		return "", err
 	}
-	f.Close()
+	// Persist the contents to disk before the caller renames it into place,
+	// so that a crash or power loss between the write and the rename cannot
+	// leave a zero-length keyfile at the final path.
+	if err := f.Sync(); err != nil {
+		f.Close()
+		os.Remove(f.Name())
+		return "", err
+	}
+	if err := f.Close(); err != nil {
+		os.Remove(f.Name())
+		return "", err
+	}
 	return f.Name(), nil
 }