diff --git a/scripts/west_commands/runners/teensy.py b/scripts/west_commands/runners/teensy.py
index efd04692c9d..dbf093b17ef 100644
--- a/scripts/west_commands/runners/teensy.py
+++ b/scripts/west_commands/runners/teensy.py
@@ -60,4 +60,4 @@ class TeensyBinaryRunner(ZephyrBinaryRunner):
             self.check_output(cmd)
             self.logger.info('Success')
         except subprocess.CalledProcessError as grepexc:
-            self.logger.error("Failure %i" % grepexc.returncode)
+            self.logger.error(f"Failure {grepexc.returncode}")