diff --git a/CODEOWNERS b/CODEOWNERS
index b346eb7a90..c00a4cfeaf 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -216,7 +216,7 @@
 /dts/posix/                               @aescolar @vanwinkeljan
 /dts/bindings/sensor/*bme680*             @BoschSensortec
 /dts/bindings/sensor/st*                  @avisconti
-/ext/hal/cmsis/                           @MaureenHelm @galak
+/ext/hal/cmsis/                           @MaureenHelm @galak @stephanosio
 /ext/lib/crypto/tinycrypt/                @ceolin
 /include/                                 @nashif @carlescufi @galak @MaureenHelm
 /include/drivers/adc.h                    @anangl