diff --git a/CHANGELOG.md b/CHANGELOG.md
index b46baaab..7520f8e9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 1.0.0-b17
 
 * Change implicit to default value in example
+* Tidy up some declarations
 
 --------------------------------------------------------------------------------
 
diff --git a/include/beast/core/buffer_cat.hpp b/include/beast/core/buffer_cat.hpp
index dee9c3c8..36f7e37f 100644
--- a/include/beast/core/buffer_cat.hpp
+++ b/include/beast/core/buffer_cat.hpp
@@ -45,7 +45,7 @@ buffer_cat(B1 const& b1, B2 const& b2, Bn const&... bn)
 {
     return detail::buffer_cat_helper<
         boost::asio::const_buffer,
-            B1, B2, Bn...>(b1, b2, bn...);
+            B1, B2, Bn...>{b1, b2, bn...};
 }
 
 } // beast
diff --git a/include/beast/core/detail/stream_concepts.hpp b/include/beast/core/detail/stream_concepts.hpp
index 416ba878..7dcf0806 100644
--- a/include/beast/core/detail/stream_concepts.hpp
+++ b/include/beast/core/detail/stream_concepts.hpp
@@ -11,7 +11,6 @@
 #include <beast/core/buffer_concepts.hpp>
 #include <beast/core/error.hpp>
 #include <boost/asio/io_service.hpp>
-#include <boost/system/error_code.hpp>
 #include <type_traits>
 #include <utility>
 
diff --git a/include/beast/core/dynabuf_readstream.hpp b/include/beast/core/dynabuf_readstream.hpp
index be7465f4..458bcc2c 100644
--- a/include/beast/core/dynabuf_readstream.hpp
+++ b/include/beast/core/dynabuf_readstream.hpp
@@ -16,7 +16,6 @@
 #include <beast/core/detail/get_lowest_layer.hpp>
 #include <boost/asio/buffer.hpp>
 #include <boost/asio/io_service.hpp>
-#include <boost/system/error_code.hpp>
 #include <cstdint>
 #include <utility>
 
diff --git a/include/beast/core/handler_alloc.hpp b/include/beast/core/handler_alloc.hpp
index dfb94aa0..b10ed8e2 100644
--- a/include/beast/core/handler_alloc.hpp
+++ b/include/beast/core/handler_alloc.hpp
@@ -23,12 +23,13 @@ namespace beast {
 
     This allocator uses the handler customizations `asio_handler_allocate`
     and `asio_handler_deallocate` to manage memory. It meets the requirements
-    of `Allocator` and can be used anywhere a `std::allocator` is
+    of @b Allocator and can be used anywhere a `std::allocator` is
     accepted.
 
     @tparam T The type of objects allocated by the allocator.
 
-    @tparam CompletionHandler The type of handler.
+    @tparam CompletionHandler The type of handler. Copies will be made
+    of the handler as needed.
 
     @note Allocated memory is only valid until the handler is called. The
     caller is still responsible for freeing memory.
diff --git a/include/beast/core/impl/dynabuf_readstream.ipp b/include/beast/core/impl/dynabuf_readstream.ipp
index 73e75afc..5403536e 100644
--- a/include/beast/core/impl/dynabuf_readstream.ipp
+++ b/include/beast/core/impl/dynabuf_readstream.ipp
@@ -9,10 +9,9 @@
 #define BEAST_IMPL_DYNABUF_READSTREAM_HPP
 
 #include <beast/core/bind_handler.hpp>
+#include <beast/core/error.hpp>
 #include <beast/core/handler_concepts.hpp>
 #include <beast/core/handler_alloc.hpp>
-#include <boost/system/error_code.hpp>
-#include <boost/system/system_error.hpp>
 
 namespace beast {
 
diff --git a/include/beast/http/basic_parser_v1.hpp b/include/beast/http/basic_parser_v1.hpp
index 317c607a..24e79fc8 100644
--- a/include/beast/http/basic_parser_v1.hpp
+++ b/include/beast/http/basic_parser_v1.hpp
@@ -513,9 +513,6 @@ private:
     bool
     needs_eof(std::false_type) const;
 
-    template<class...>
-    using void_t = void;
-
     template<class C>
     class check_on_start_t
     {
diff --git a/include/beast/http/detail/basic_parser_v1.hpp b/include/beast/http/detail/basic_parser_v1.hpp
index 196089bc..b5370099 100644
--- a/include/beast/http/detail/basic_parser_v1.hpp
+++ b/include/beast/http/detail/basic_parser_v1.hpp
@@ -8,9 +8,6 @@
 #ifndef BEAST_HTTP_DETAIL_BASIC_PARSER_V1_HPP
 #define BEAST_HTTP_DETAIL_BASIC_PARSER_V1_HPP
 
-#include <boost/system/error_code.hpp>
-#include <boost/utility/string_ref.hpp>
-#include <array>
 #include <cstdint>
 
 namespace beast {
diff --git a/include/beast/http/impl/write.ipp b/include/beast/http/impl/write.ipp
index 81df375c..02628f4b 100644
--- a/include/beast/http/impl/write.ipp
+++ b/include/beast/http/impl/write.ipp
@@ -109,9 +109,6 @@ write_fields(DynamicBuffer& dynabuf, FieldSequence const& fields)
 template<bool isRequest, class Body, class Headers>
 struct write_preparation
 {
-    using headers_type =
-        basic_headers<std::allocator<char>>;
-
     message_v1<isRequest, Body, Headers> const& msg;
     typename Body::writer w;
     streambuf sb;