diff --git a/.travis.yml b/.travis.yml
index 4be5ef26..17d8f03d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -28,59 +28,65 @@ env:
 matrix:
   include:
     # gcc
-    - env: CONF=release ARCH=x86    CXX11=ON CXX17=OFF
+    - env: CONF=release ARCH=x86     CXX11=ON  CXX17=OFF MEMBERSMAP=OFF
       compiler: gcc
       arch: amd64
-    - env: CONF=release ARCH=x86_64 CXX11=ON CXX17=OFF
+    - env: CONF=release ARCH=x86_64  CXX11=ON  CXX17=OFF MEMBERSMAP=OFF
       compiler: gcc
       arch: amd64
-    - env: CONF=debug   ARCH=x86    CXX11=OFF CXX17=OFF
+    - env: CONF=release ARCH=x86_64  CXX11=ON  CXX17=OFF MEMBERSMAP=ON
       compiler: gcc
       arch: amd64
-    - env: CONF=debug   ARCH=x86_64 CXX11=OFF CXX17=OFF
+    - env: CONF=debug   ARCH=x86     CXX11=OFF CXX17=OFF MEMBERSMAP=OFF
       compiler: gcc
       arch: amd64
-    - env: CONF=debug   ARCH=x86    CXX11=OFF CXX17=ON CXX_FLAGS='-D_GLIBCXX_DEBUG'
-      compiler: gcc
-      arch: amd64/
-    - env: CONF=debug   ARCH=x86_64 CXX11=OFF CXX17=ON CXX_FLAGS='-D_GLIBCXX_DEBUG'
+    - env: CONF=debug   ARCH=x86_64  CXX11=OFF CXX17=OFF MEMBERSMAP=OFF
       compiler: gcc
       arch: amd64
-    - env: CONF=release ARCH=aarch64 CXX11=ON CXX17=OFF
+    - env: CONF=debug   ARCH=x86     CXX11=OFF CXX17=ON  MEMBERSMAP=ON CXX_FLAGS='-D_GLIBCXX_DEBUG'
+      compiler: gcc
+      arch: amd64
+    - env: CONF=debug   ARCH=x86_64  CXX11=OFF CXX17=ON  MEMBERSMAP=ON CXX_FLAGS='-D_GLIBCXX_DEBUG'
+      compiler: gcc
+      arch: amd64
+    - env: CONF=release ARCH=aarch64 CXX11=ON  CXX17=OFF MEMBERSMAP=OFF
       compiler: gcc
       arch: arm64
-    - env: CONF=release ARCH=aarch64 CXX11=OFF CXX17=OFF
+    - env: CONF=release ARCH=aarch64 CXX11=OFF CXX17=OFF MEMBERSMAP=OFF
       compiler: gcc
       arch: arm64
-    - env: CONF=release ARCH=aarch64 CXX11=OFF CXX17=ON
+    - env: CONF=release ARCH=aarch64 CXX11=OFF CXX17=ON  MEMBERSMAP=ON
       compiler: gcc
       arch: arm64
     # clang
-    - env: CONF=release ARCH=x86    CXX11=ON CXX17=OFF CCACHE_CPP2=yes
+    - env: CONF=release ARCH=x86     CXX11=ON  CXX17=OFF MEMBERSMAP=ON  CCACHE_CPP2=yes
       compiler: clang
       arch: amd64
-    - env: CONF=release ARCH=x86_64 CXX11=ON CXX17=OFF CCACHE_CPP2=yes
+    - env: CONF=release ARCH=x86_64  CXX11=ON  CXX17=OFF MEMBERSMAP=ON  CCACHE_CPP2=yes
       compiler: clang
       arch: amd64
-    - env: CONF=debug   ARCH=x86    CXX11=OFF CXX17=OFF CCACHE_CPP2=yes
+    - env: CONF=release ARCH=x86_64  CXX11=ON  CXX17=OFF MEMBERSMAP=OFF CCACHE_CPP2=yes
       compiler: clang
       arch: amd64
-    - env: CONF=debug   ARCH=x86_64 CXX11=OFF CXX17=OFF CCACHE_CPP2=yes
+    - env: CONF=debug   ARCH=x86     CXX11=OFF CXX17=OFF MEMBERSMAP=ON  CCACHE_CPP2=yes
       compiler: clang
       arch: amd64
-    - env: CONF=debug   ARCH=x86    CXX11=OFF CXX17=ON CCACHE_CPP2=yes
+    - env: CONF=debug   ARCH=x86_64  CXX11=OFF CXX17=OFF MEMBERSMAP=ON  CCACHE_CPP2=yes
       compiler: clang
       arch: amd64
-    - env: CONF=debug   ARCH=x86_64 CXX11=OFF CXX17=ON CCACHE_CPP2=yes
+    - env: CONF=debug   ARCH=x86     CXX11=OFF CXX17=ON  MEMBERSMAP=OFF CCACHE_CPP2=yes
       compiler: clang
       arch: amd64
-    - env: CONF=debug   ARCH=aarch64 CXX11=ON CXX17=OFF CCACHE_CPP2=yes
+    - env: CONF=debug   ARCH=x86_64  CXX11=OFF CXX17=ON  MEMBERSMAP=OFF CCACHE_CPP2=yes
+      compiler: clang
+      arch: amd64
+    - env: CONF=debug   ARCH=aarch64 CXX11=ON  CXX17=OFF MEMBERSMAP=ON  CCACHE_CPP2=yes
       compiler: clang
       arch: arm64
-    - env: CONF=debug   ARCH=aarch64 CXX11=OFF CXX17=OFF CCACHE_CPP2=yes
+    - env: CONF=debug   ARCH=aarch64 CXX11=OFF CXX17=OFF MEMBERSMAP=ON  CCACHE_CPP2=yes
       compiler: clang
       arch: arm64
-    - env: CONF=debug   ARCH=aarch64 CXX11=OFF CXX17=ON CCACHE_CPP2=yes
+    - env: CONF=debug   ARCH=aarch64 CXX11=OFF CXX17=ON  MEMBERSMAP=OFF CCACHE_CPP2=yes
       compiler: clang
       arch: arm64
     # coverage report
@@ -93,7 +99,7 @@ matrix:
       after_success:
         - pip install --user cpp-coveralls
         - coveralls -r .. --gcov-options '\-lp' -e thirdparty -e example -e test -e build/CMakeFiles -e include/rapidjson/msinttypes -e include/rapidjson/internal/meta.h -e include/rapidjson/error/en.h
-    - env: CONF=debug   ARCH=x86_64  GCOV_FLAGS='--coverage' CXX_FLAGS='-O0' CXX11=ON CXX17=OFF
+    - env: CONF=debug   ARCH=x86_64  GCOV_FLAGS='--coverage' CXX_FLAGS='-O0' CXX11=ON  CXX17=OFF MEMBERSMAP=ON
       compiler: gcc
       arch: amd64
       cache:
@@ -146,6 +152,7 @@ script:
       eval "ARCH_FLAGS=\${ARCH_FLAGS_${ARCH}}" ;
       (cd build && cmake
       -DRAPIDJSON_HAS_STDSTRING=ON
+      -DRAPIDJSON_USE_MEMBERSMAP=$MEMBERSMAP
       -DRAPIDJSON_BUILD_CXX11=$CXX11
       -DRAPIDJSON_BUILD_CXX17=$CXX17
       -DCMAKE_VERBOSE_MAKEFILE=ON
diff --git a/appveyor.yml b/appveyor.yml
index 2e591ee6..4044ba66 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -15,70 +15,83 @@ environment:
     VS_PLATFORM: win32
     CXX11: OFF
     CXX17: OFF
+    MEMBERSMAP: OFF
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
     VS_VERSION: 10 2010
     VS_PLATFORM: x64
     CXX11: OFF
     CXX17: OFF
+    MEMBERSMAP: ON
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
     VS_VERSION: 11 2012
     VS_PLATFORM: win32
     CXX11: OFF
     CXX17: OFF
+    MEMBERSMAP: ON
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
     VS_VERSION: 11 2012
     VS_PLATFORM: x64
     CXX11: OFF
     CXX17: OFF
+    MEMBERSMAP: OFF
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
     VS_VERSION: 12 2013
     VS_PLATFORM: win32
     CXX11: OFF
     CXX17: OFF
+    MEMBERSMAP: OFF
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
     VS_VERSION: 12 2013
     VS_PLATFORM: x64
     CXX11: OFF
     CXX17: OFF
+    MEMBERSMAP: ON
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
     VS_VERSION: 14 2015
     VS_PLATFORM: win32
     CXX11: OFF
     CXX17: OFF
+    MEMBERSMAP: ON
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
     VS_VERSION: 14 2015
     VS_PLATFORM: x64
     CXX11: OFF
     CXX17: OFF
+    MEMBERSMAP: OFF
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
     VS_VERSION: 15 2017
     VS_PLATFORM: win32
     CXX11: OFF
     CXX17: OFF
+    MEMBERSMAP: OFF
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
     VS_VERSION: 15 2017
     VS_PLATFORM: x64
     CXX11: OFF
     CXX17: OFF
+    MEMBERSMAP: ON
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
     VS_VERSION: 15 2017
     VS_PLATFORM: x64
     CXX11: ON
     CXX17: OFF
+    MEMBERSMAP: OFF
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
     VS_VERSION: 15 2017
     VS_PLATFORM: x64
     CXX11: OFF
     CXX17: ON
+    MEMBERSMAP: OFF
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     VS_VERSION: 16 2019
     VS_PLATFORM: x64
     CXX11: OFF
     CXX17: ON
+    MEMBERSMAP: ON
 
 before_build:
 - git submodule update --init --recursive
-- cmake -H. -BBuild/VS -G "Visual Studio %VS_VERSION%" -DCMAKE_GENERATOR_PLATFORM=%VS_PLATFORM% -DCMAKE_VERBOSE_MAKEFILE=ON -DBUILD_SHARED_LIBS=true -DRAPIDJSON_BUILD_CXX11=%CXX11% -DRAPIDJSON_BUILD_CXX17=%CXX17% -Wno-dev
+- cmake -H. -BBuild/VS -G "Visual Studio %VS_VERSION%" -DCMAKE_GENERATOR_PLATFORM=%VS_PLATFORM% -DCMAKE_VERBOSE_MAKEFILE=ON -DBUILD_SHARED_LIBS=true -DRAPIDJSON_BUILD_CXX11=%CXX11% -DRAPIDJSON_BUILD_CXX17=%CXX17% -DRAPIDJSON_USE_MEMBERSMAP=%MEMBERSMAP% -Wno-dev
 
 build:
   project: Build\VS\RapidJSON.sln