diff --git a/camera/ndk/impl/ACameraCaptureSession.h b/camera/ndk/impl/ACameraCaptureSession.h
index 58428e6..f56219c 100644
--- a/camera/ndk/impl/ACameraCaptureSession.h
+++ b/camera/ndk/impl/ACameraCaptureSession.h
@@ -24,7 +24,7 @@
 using namespace android;
 
 struct ACaptureSessionOutput {
-    ACaptureSessionOutput(ANativeWindow* window) : mWindow(window) {};
+    explicit ACaptureSessionOutput(ANativeWindow* window) : mWindow(window) {};
 
     bool operator == (const ACaptureSessionOutput& other) const {
         return mWindow == other.mWindow;
diff --git a/camera/ndk/impl/ACameraDevice.h b/camera/ndk/impl/ACameraDevice.h
index 71e364d..051462b 100644
--- a/camera/ndk/impl/ACameraDevice.h
+++ b/camera/ndk/impl/ACameraDevice.h
@@ -65,7 +65,7 @@
     // Callbacks from camera service
     class ServiceCallback : public hardware::camera2::BnCameraDeviceCallbacks {
       public:
-        ServiceCallback(CameraDevice* device) : mDevice(device) {}
+        explicit ServiceCallback(CameraDevice* device) : mDevice(device) {}
         binder::Status onDeviceError(int32_t errorCode,
                            const CaptureResultExtras& resultExtras) override;
         binder::Status onDeviceIdle() override;
diff --git a/camera/ndk/impl/ACameraManager.h b/camera/ndk/impl/ACameraManager.h
index 3f2262f..5b88904 100644
--- a/camera/ndk/impl/ACameraManager.h
+++ b/camera/ndk/impl/ACameraManager.h
@@ -60,7 +60,7 @@
 
     class DeathNotifier : public IBinder::DeathRecipient {
       public:
-        DeathNotifier(CameraManagerGlobal* cm) : mCameraManager(cm) {}
+        explicit DeathNotifier(CameraManagerGlobal* cm) : mCameraManager(cm) {}
       protected:
         // IBinder::DeathRecipient implementation
         virtual void binderDied(const wp<IBinder>& who);
@@ -71,7 +71,7 @@
 
     class CameraServiceListener final : public hardware::BnCameraServiceListener {
       public:
-        CameraServiceListener(CameraManagerGlobal* cm) : mCameraManager(cm) {}
+        explicit CameraServiceListener(CameraManagerGlobal* cm) : mCameraManager(cm) {}
         virtual binder::Status onStatusChanged(int32_t status, int32_t cameraId);
 
         // Torch API not implemented yet
@@ -86,7 +86,7 @@
 
     // Wrapper of ACameraManager_AvailabilityCallbacks so we can store it in std::set
     struct Callback {
-        Callback(const ACameraManager_AvailabilityCallbacks *callback) :
+        explicit Callback(const ACameraManager_AvailabilityCallbacks *callback) :
             mAvailable(callback->onCameraAvailable),
             mUnavailable(callback->onCameraUnavailable),
             mContext(callback->context) {}
diff --git a/camera/ndk/impl/ACaptureRequest.h b/camera/ndk/impl/ACaptureRequest.h
index 6bd8406..3ef6a84 100644
--- a/camera/ndk/impl/ACaptureRequest.h
+++ b/camera/ndk/impl/ACaptureRequest.h
@@ -22,7 +22,7 @@
 using namespace android;
 
 struct ACameraOutputTarget {
-    ACameraOutputTarget(ANativeWindow* window) : mWindow(window) {};
+    explicit ACameraOutputTarget(ANativeWindow* window) : mWindow(window) {};
 
     bool operator == (const ACameraOutputTarget& other) const {
         return mWindow == other.mWindow;