diff --git a/src/serializer.cpp b/src/serializer.cpp
index e0727916..5fb6633d 100644
--- a/src/serializer.cpp
+++ b/src/serializer.cpp
@@ -542,11 +542,7 @@ serializer::
 stream::
 capacity() const
 {
-    auto const n =
-        chunked_overhead_ +
-            2 + // CRLF
-            5;  // final chunk
-    return sr_->tmp0_.capacity() - n; // VFALCO ?
+    return sr_->tmp0_.capacity();
 }
 
 std::size_t
diff --git a/test/unit/serializer.cpp b/test/unit/serializer.cpp
index 1302553f..bfbfd304 100644
--- a/test/unit/serializer.cpp
+++ b/test/unit/serializer.cpp
@@ -274,6 +274,9 @@ struct serializer_test
 
         serializer sr(sr_capacity);
         auto stream = sr.start_stream(res);
+        BOOST_TEST_EQ(stream.size(), 0);
+        BOOST_TEST_GT(stream.capacity(), 0);
+        BOOST_TEST_LE(stream.capacity(), sr_capacity);
 
         std::vector<char> s; // stores complete output
 
@@ -292,6 +295,11 @@ struct serializer_test
 
             stream.commit(bs);
             body.remove_prefix(bs);
+            if(! res.chunked() )
+                BOOST_TEST_EQ(stream.size(), bs);
+            else
+                // chunk overhead: header + \r\n
+                BOOST_TEST_EQ(stream.size(), bs + 18 + 2);
         };
 
         auto consume_body_buffer = [&](
@@ -339,6 +347,7 @@ struct serializer_test
 
             for(auto pos = cbs.begin(); pos != end; ++pos)
                 consume_body_buffer(*pos);
+            BOOST_TEST_EQ(stream.size(), 0);
         }
 
         BOOST_TEST_THROWS(stream.close(), std::logic_error);
diff --git a/toolchain.cmake b/toolchain.cmake
new file mode 100644
index 00000000..62980ed5
--- /dev/null
+++ b/toolchain.cmake
@@ -0,0 +1,5 @@
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_FLAGS_INIT "-Wall -Wextra --coverage")
+set(BUILD_TESTING ON)
+set(CMAKE_EXE_LINKER_FLAGS_INIT "--coverage")
+# add_link_options("--coverage")