diff --git a/drm/libmediadrm/Drm.cpp b/drm/libmediadrm/Drm.cpp
index 7c1f5c8..9ab08db 100644
--- a/drm/libmediadrm/Drm.cpp
+++ b/drm/libmediadrm/Drm.cpp
@@ -61,7 +61,7 @@
 }
 
 struct DrmSessionClient : public DrmSessionClientInterface {
-    DrmSessionClient(Drm* drm) : mDrm(drm) {}
+    explicit DrmSessionClient(Drm* drm) : mDrm(drm) {}
 
     virtual bool reclaimSession(const Vector<uint8_t>& sessionId) {
         sp<Drm> drm = mDrm.promote();
diff --git a/media/libmedia/IMediaCodecService.cpp b/media/libmedia/IMediaCodecService.cpp
index dcf2b27..2d62419 100644
--- a/media/libmedia/IMediaCodecService.cpp
+++ b/media/libmedia/IMediaCodecService.cpp
@@ -33,7 +33,7 @@
 class BpMediaCodecService : public BpInterface<IMediaCodecService>
 {
 public:
-    BpMediaCodecService(const sp<IBinder>& impl)
+    explicit BpMediaCodecService(const sp<IBinder>& impl)
         : BpInterface<IMediaCodecService>(impl)
     {
     }
diff --git a/media/libmedia/IMediaDrmService.cpp b/media/libmedia/IMediaDrmService.cpp
index 9b6ecfd..84812dc 100644
--- a/media/libmedia/IMediaDrmService.cpp
+++ b/media/libmedia/IMediaDrmService.cpp
@@ -37,7 +37,7 @@
 class BpMediaDrmService: public BpInterface<IMediaDrmService>
 {
 public:
-    BpMediaDrmService(const sp<IBinder>& impl)
+    explicit BpMediaDrmService(const sp<IBinder>& impl)
         : BpInterface<IMediaDrmService>(impl)
     {
     }
diff --git a/media/libmedia/IMediaExtractor.cpp b/media/libmedia/IMediaExtractor.cpp
index f142ccc..2a4c669 100644
--- a/media/libmedia/IMediaExtractor.cpp
+++ b/media/libmedia/IMediaExtractor.cpp
@@ -43,7 +43,7 @@
 
 class BpMediaExtractor : public BpInterface<IMediaExtractor> {
 public:
-    BpMediaExtractor(const sp<IBinder>& impl)
+    explicit BpMediaExtractor(const sp<IBinder>& impl)
         : BpInterface<IMediaExtractor>(impl)
     {
     }
diff --git a/media/libmedia/IMediaExtractorService.cpp b/media/libmedia/IMediaExtractorService.cpp
index dcbbde2..4276bcd 100644
--- a/media/libmedia/IMediaExtractorService.cpp
+++ b/media/libmedia/IMediaExtractorService.cpp
@@ -33,7 +33,7 @@
 class BpMediaExtractorService : public BpInterface<IMediaExtractorService>
 {
 public:
-    BpMediaExtractorService(const sp<IBinder>& impl)
+    explicit BpMediaExtractorService(const sp<IBinder>& impl)
         : BpInterface<IMediaExtractorService>(impl)
     {
     }
diff --git a/media/libmedia/IMediaSource.cpp b/media/libmedia/IMediaSource.cpp
index 84f1181..1db22ec 100644
--- a/media/libmedia/IMediaSource.cpp
+++ b/media/libmedia/IMediaSource.cpp
@@ -106,7 +106,7 @@
 
 class BpMediaSource : public BpInterface<IMediaSource> {
 public:
-    BpMediaSource(const sp<IBinder>& impl)
+    explicit BpMediaSource(const sp<IBinder>& impl)
         : BpInterface<IMediaSource>(impl)
     {
     }
diff --git a/media/libstagefright/MediaExtractor.cpp b/media/libstagefright/MediaExtractor.cpp
index 1c6c882..6c9c562 100644
--- a/media/libstagefright/MediaExtractor.cpp
+++ b/media/libstagefright/MediaExtractor.cpp
@@ -93,7 +93,7 @@
     sp<IMemory> mMemory;
     sp<DataSource> mSource;
     String8 mName;
-    RemoteDataSource(const sp<DataSource> &source);
+    explicit RemoteDataSource(const sp<DataSource> &source);
     DISALLOW_EVIL_CONSTRUCTORS(RemoteDataSource);
 };