diff --git a/.github/workflows/unittest_uwp.yml b/.github/workflows/unittest_uwp.yml
index d37763c0..5ec0d228 100644
--- a/.github/workflows/unittest_uwp.yml
+++ b/.github/workflows/unittest_uwp.yml
@@ -13,7 +13,7 @@ jobs:
     - run: |
         mkdir build
         cd build
-        cmake -DCMAKE_TOOLCHAIN_FILE=c:/vcpkg/scripts/buildsystems/vcpkg.cmake -DCMAKE_SYSTEM_NAME=WindowsStore -DCMAKE_SYSTEM_VERSION="10.0" -DCMAKE_CXX_COMPILER=cl.exe -DUSE_TEST=1 -DUSE_ZLIB=0 ..
+        cmake -DCMAKE_TOOLCHAIN_FILE=c:/vcpkg/scripts/buildsystems/vcpkg.cmake -DCMAKE_SYSTEM_NAME=WindowsStore -DCMAKE_SYSTEM_VERSION="10.0" -DCMAKE_CXX_COMPILER=cl.exe -DCMAKE_UNITY_BUILD=ON -DUSE_TEST=1 -DUSE_ZLIB=0 ..
     - run: cmake --build build
 
 #
diff --git a/.github/workflows/unittest_windows.yml b/.github/workflows/unittest_windows.yml
index 4fe63e6c..e88c24c5 100644
--- a/.github/workflows/unittest_windows.yml
+++ b/.github/workflows/unittest_windows.yml
@@ -13,7 +13,7 @@ jobs:
     - run: |
         mkdir build
         cd build
-        cmake -DCMAKE_CXX_COMPILER=cl.exe -DUSE_WS=1 -DUSE_TEST=1 -DUSE_ZLIB=0 ..
+        cmake -DCMAKE_UNITY_BUILD=ON -DCMAKE_CXX_COMPILER=cl.exe -DUSE_WS=1 -DUSE_TEST=1 -DUSE_ZLIB=0 ..
     - run: cmake --build build
 
 #- run: ../build/test/ixwebsocket_unittest.exe
diff --git a/makefile.dev b/makefile.dev
index 75cc7049..b4a86e89 100644
--- a/makefile.dev
+++ b/makefile.dev
@@ -22,13 +22,13 @@ install: brew
 # Default rule does not use python as that requires first time users to have Python3 installed
 #
 brew:
-	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_WS=1 -DUSE_TEST=1 .. ; ninja install)
+	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_UNITY_BUILD=ON -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_WS=1 -DUSE_TEST=1 .. ; ninja install)
 
 # Docker default target. We've had problems with OpenSSL and TLS 1.3 (on the
 # server side ?) and I can't work-around it easily, so we're using mbedtls on
 # Linux for the SSL backend, which works great.
 ws_mbedtls_install:
-	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_BUILD_TYPE=MinSizeRel -DUSE_ZLIB=OFF -DUSE_TLS=1 -DUSE_WS=1 -DUSE_MBED_TLS=1 .. ; ninja install)
+	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_UNITY_BUILD=ON -DCMAKE_BUILD_TYPE=MinSizeRel -DUSE_ZLIB=OFF -DUSE_TLS=1 -DUSE_WS=1 -DUSE_MBED_TLS=1 .. ; ninja install)
 
 ws:
 	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_WS=1 .. && ninja install)
@@ -111,27 +111,27 @@ test_server:
 	(cd test && npm i ws && node broadcast-server.js)
 
 test:
-	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_TEST=1 ..)
+	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_UNITY_BUILD=ON -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_TEST=1 ..)
 	(cd build ; ninja)
 	(cd build ; ninja test)
 
 test_asan:
-	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_TEST=1 .. -DCMAKE_C_FLAGS="-fsanitize=address -fno-omit-frame-pointer" -DCMAKE_CXX_FLAGS="-fsanitize=address -fno-omit-frame-pointer")
+	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_UNITY_BUILD=ON -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_TEST=1 .. -DCMAKE_C_FLAGS="-fsanitize=address -fno-omit-frame-pointer" -DCMAKE_CXX_FLAGS="-fsanitize=address -fno-omit-frame-pointer")
 	(cd build ; ninja)
 	(cd build ; ctest -V .)
 
 test_tsan_mbedtls:
-	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_MBED_TLS=1 -DUSE_TEST=1 .. -DCMAKE_C_FLAGS="-fsanitize=thread -fno-omit-frame-pointer" -DCMAKE_CXX_FLAGS="-fsanitize=thread -fno-omit-frame-pointer")
+	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_UNITY_BUILD=ON -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_MBED_TLS=1 -DUSE_TEST=1 .. -DCMAKE_C_FLAGS="-fsanitize=thread -fno-omit-frame-pointer" -DCMAKE_CXX_FLAGS="-fsanitize=thread -fno-omit-frame-pointer")
 	(cd build ; ninja)
 	(cd build ; ninja test)
 
 test_tsan_openssl:
-	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_OPENS_SSL=1 -DUSE_TEST=1 .. -DCMAKE_C_FLAGS="-fsanitize=thread -fno-omit-frame-pointer" -DCMAKE_CXX_FLAGS="-fsanitize=thread -fno-omit-frame-pointer")
+	mkdir -p build && (cd build ; cmake -GNinja --DCMAKE_UNITY_BUILD=ON DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_OPENS_SSL=1 -DUSE_TEST=1 .. -DCMAKE_C_FLAGS="-fsanitize=thread -fno-omit-frame-pointer" -DCMAKE_CXX_FLAGS="-fsanitize=thread -fno-omit-frame-pointer")
 	(cd build ; ninja)
 	(cd build ; ninja test)
 
 test_tsan_sectransport:
-	mkdir -p build && (cd build ; cmake -GNinja -DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_OPENS_SSL=1 -DUSE_TEST=1 .. -DCMAKE_C_FLAGS="-fsanitize=thread -fno-omit-frame-pointer" -DCMAKE_CXX_FLAGS="-fsanitize=thread -fno-omit-frame-pointer")
+	mkdir -p build && (cd build ; cmake -GNinja --DCMAKE_UNITY_BUILD=ON DCMAKE_BUILD_TYPE=Debug -DUSE_TLS=1 -DUSE_OPENS_SSL=1 -DUSE_TEST=1 .. -DCMAKE_C_FLAGS="-fsanitize=thread -fno-omit-frame-pointer" -DCMAKE_CXX_FLAGS="-fsanitize=thread -fno-omit-frame-pointer")
 	(cd build ; ninja)
 	(cd build ; ninja test)