diff --git a/libs/input/PointerController.cpp b/libs/input/PointerController.cpp
index 0a90f85cda0e0..6c5f20c1d4162 100644
--- a/libs/input/PointerController.cpp
+++ b/libs/input/PointerController.cpp
@@ -39,7 +39,7 @@ protected:
     virtual ~WeakLooperCallback() { }
 
 public:
-    WeakLooperCallback(const wp<LooperCallback>& callback) :
+    explicit WeakLooperCallback(const wp<LooperCallback>& callback) :
         mCallback(callback) {
     }
 
diff --git a/libs/protoutil/include/android/util/EncodedBuffer.h b/libs/protoutil/include/android/util/EncodedBuffer.h
index c84de4c1c0834..0b7f6e46be659 100644
--- a/libs/protoutil/include/android/util/EncodedBuffer.h
+++ b/libs/protoutil/include/android/util/EncodedBuffer.h
@@ -38,13 +38,13 @@ class EncodedBuffer
 {
 public:
     EncodedBuffer();
-    EncodedBuffer(size_t chunkSize);
+    explicit EncodedBuffer(size_t chunkSize);
     ~EncodedBuffer();
 
     class Pointer {
     public:
         Pointer();
-        Pointer(size_t chunkSize);
+        explicit Pointer(size_t chunkSize);
 
         size_t pos() const;
         size_t index() const;
@@ -161,7 +161,7 @@ public:
     friend class iterator;
     class iterator {
     public:
-        iterator(const EncodedBuffer& buffer);
+        explicit iterator(const EncodedBuffer& buffer);
 
         /**
          * Returns the number of bytes written in the buffer