--- a/gfx/angle/src/common/bitset_utils.h
+++ b/gfx/angle/src/common/bitset_utils.h
@@ -30,17 +30,17 @@ class BitSetT final
     {
       public:
         ~Reference() {}
         Reference &operator=(bool x)
         {
             mParent->set(mBit, x);
             return *this;
         }
-        operator bool() const { return mParent->test(mBit); }
+        explicit operator bool() const { return mParent->test(mBit); }
 
       private:
         friend class BitSetT;
 
         Reference(BitSetT *parent, std::size_t bit) : mParent(parent), mBit(bit) {}
 
         BitSetT *mParent;
         std::size_t mBit;

--- a/gfx/angle/src/libANGLE/VertexAttribute.h
+++ b/gfx/angle/src/libANGLE/VertexAttribute.h
@@ -18,17 +18,17 @@ class VertexArray;
 //
 // Implementation of Generic Vertex Attribute Bindings for ES3.1. The members are intentionally made
 // private in order to hide implementation details.
 //
 class VertexBinding final : angle::NonCopyable
 {
   public:
     VertexBinding();
-    explicit VertexBinding(VertexBinding &&binding);
+    VertexBinding(VertexBinding &&binding);
     VertexBinding &operator=(VertexBinding &&binding);
 
     GLuint getStride() const { return mStride; }
     void setStride(GLuint strideIn) { mStride = strideIn; }
 
     GLuint getDivisor() const { return mDivisor; }
     void setDivisor(GLuint divisorIn) { mDivisor = divisorIn; }
 
@@ -47,17 +47,17 @@ class VertexBinding final : angle::NonCo
 };
 
 //
 // Implementation of Generic Vertex Attributes for ES3.1
 //
 struct VertexAttribute final : private angle::NonCopyable
 {
     explicit VertexAttribute(GLuint bindingIndex);
-    explicit VertexAttribute(VertexAttribute &&attrib);
+    VertexAttribute(VertexAttribute &&attrib);
     VertexAttribute &operator=(VertexAttribute &&attrib);
 
     bool enabled;  // For glEnable/DisableVertexAttribArray
     GLenum type;
     GLuint size;
     bool normalized;
     bool pureInteger;