diff --git a/soundtrigger/ISoundTriggerHwService.cpp b/soundtrigger/ISoundTriggerHwService.cpp
index e37bae3..d44f5cb 100644
--- a/soundtrigger/ISoundTriggerHwService.cpp
+++ b/soundtrigger/ISoundTriggerHwService.cpp
@@ -45,7 +45,7 @@
 class BpSoundTriggerHwService: public BpInterface<ISoundTriggerHwService>
 {
 public:
-    BpSoundTriggerHwService(const sp<IBinder>& impl)
+    explicit BpSoundTriggerHwService(const sp<IBinder>& impl)
         : BpInterface<ISoundTriggerHwService>(impl)
     {
     }