diff --git a/src/asio_client_session.cc b/src/asio_client_session.cc
index a5acffc7..5cf01c74 100644
--- a/src/asio_client_session.cc
+++ b/src/asio_client_session.cc
@@ -154,7 +154,7 @@ const nghttp2_priority_spec *priority_spec::get() const {
   return &spec_;
 }
 
-const bool priority_spec::valid() const { return valid_; }
+bool priority_spec::valid() const { return valid_; }
 
 } // namespace client
 } // namespace asio_http2
diff --git a/src/includes/nghttp2/asio_http2_client.h b/src/includes/nghttp2/asio_http2_client.h
index 7b256a76..59ba9b26 100644
--- a/src/includes/nghttp2/asio_http2_client.h
+++ b/src/includes/nghttp2/asio_http2_client.h
@@ -133,7 +133,7 @@ public:
 
   // Indicates whether or not this spec is valid (i.e. was constructed with
   // values).
-  const bool valid() const;
+  bool valid() const;
 
 private:
   nghttp2_priority_spec spec_;