diff --git a/.github/workflows/unittest_uwp.yml b/.github/workflows/unittest_uwp.yml
index 4766d1ba..d37763c0 100644
--- a/.github/workflows/unittest_uwp.yml
+++ b/.github/workflows/unittest_uwp.yml
@@ -10,12 +10,10 @@ jobs:
     steps:
     - uses: actions/checkout@v1
     - uses: seanmiddleditch/gha-setup-vsdevenv@master
-    - run: |
-        vcpkg install zlib:x64-uwp
     - 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 ..
+        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 ..
     - run: cmake --build build
 
 #
diff --git a/.github/workflows/unittest_windows.yml b/.github/workflows/unittest_windows.yml
index ccd2e639..4fe63e6c 100644
--- a/.github/workflows/unittest_windows.yml
+++ b/.github/workflows/unittest_windows.yml
@@ -10,10 +10,11 @@ jobs:
     steps:
     - uses: actions/checkout@v1
     - uses: seanmiddleditch/gha-setup-vsdevenv@master
-    - run: |
-        vcpkg install zlib:x64-windows
     - run: |
         mkdir build
         cd build
-        cmake -DCMAKE_TOOLCHAIN_FILE=c:/vcpkg/scripts/buildsystems/vcpkg.cmake -DCMAKE_CXX_COMPILER=cl.exe -DUSE_WS=1 -DUSE_TEST=1 ..
+        cmake -DCMAKE_CXX_COMPILER=cl.exe -DUSE_WS=1 -DUSE_TEST=1 -DUSE_ZLIB=0 ..
     - run: cmake --build build
+
+#- run: ../build/test/ixwebsocket_unittest.exe
+# working-directory: test
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7bb567b6..4760ca77 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -190,10 +190,16 @@ if (USE_TLS)
   endif()
 endif()
 
-# Use ZLIB_ROOT CMake variable if you need to use your own zlib
-find_package(ZLIB REQUIRED)
-include_directories(${ZLIB_INCLUDE_DIRS})
-target_link_libraries(ixwebsocket ${ZLIB_LIBRARIES})
+option(USE_ZLIB "Enable zlib support" TRUE)
+
+if (USE_ZLIB)
+  # Use ZLIB_ROOT CMake variable if you need to use your own zlib
+  find_package(ZLIB REQUIRED)
+  include_directories(${ZLIB_INCLUDE_DIRS})
+  target_link_libraries(ixwebsocket ${ZLIB_LIBRARIES})
+
+  target_compile_definitions(ixwebsocket PUBLIC IXWEBSOCKET_USE_ZLIB)
+endif()
 
 if (WIN32)
   target_link_libraries(ixwebsocket wsock32 ws2_32 shlwapi)
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 7597cba1..a9873fca 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -1,6 +1,10 @@
 # Changelog
 All changes to this project will be documented in this file.
 
+## [10.1.2] - 2020-07-31
+
+(build) make using zlib optional, with the caveat that some http and websocket features are not available when zlib is absent
+
 ## [10.1.1] - 2020-07-29
 
 (websocket client) onProgressCallback not called for short messages on a websocket (fix #233)
diff --git a/docs/build.md b/docs/build.md
index 00e5895d..0c32b899 100644
--- a/docs/build.md
+++ b/docs/build.md
@@ -17,6 +17,7 @@ There is a unittest which can be executed by typing `make test`.
 
 Options for building:
 
+* `-DUSE_ZLIB=1` will enable zlib support, required for http client + server + websocket per message deflate extension
 * `-DUSE_TLS=1` will enable TLS support
 * `-DUSE_OPEN_SSL=1` will use [openssl](https://www.openssl.org/) for the TLS support (default on Linux and Windows)
 * `-DUSE_MBED_TLS=1` will use [mbedlts](https://tls.mbed.org/) for the TLS support
diff --git a/ixwebsocket/IXHttpClient.cpp b/ixwebsocket/IXHttpClient.cpp
index 49da10da..d34eeed3 100644
--- a/ixwebsocket/IXHttpClient.cpp
+++ b/ixwebsocket/IXHttpClient.cpp
@@ -16,7 +16,10 @@
 #include <random>
 #include <sstream>
 #include <vector>
+
+#ifdef IXWEBSOCKET_USE_ZLIB
 #include <zlib.h>
+#endif
 
 namespace ix
 {
@@ -174,11 +177,13 @@ namespace ix
         ss << verb << " " << path << " HTTP/1.1\r\n";
         ss << "Host: " << host << "\r\n";
 
+#ifdef IXWEBSOCKET_USE_ZLIB
         if (args->compress)
         {
             ss << "Accept-Encoding: gzip"
                << "\r\n";
         }
+#endif
 
         // Append extra headers
         for (auto&& it : args->extraHeaders)
@@ -495,6 +500,7 @@ namespace ix
 
         downloadSize = payload.size();
 
+#ifdef IXWEBSOCKET_USE_ZLIB
         // If the content was compressed with gzip, decode it
         if (headers["Content-Encoding"] == "gzip")
         {
@@ -513,6 +519,7 @@ namespace ix
             }
             payload = decompressedPayload;
         }
+#endif
 
         return std::make_shared<HttpResponse>(code,
                                               description,
@@ -672,6 +679,7 @@ namespace ix
         return ss.str();
     }
 
+#ifdef IXWEBSOCKET_USE_ZLIB
     bool HttpClient::gzipInflate(const std::string& in, std::string& out)
     {
         z_stream inflateState;
@@ -716,6 +724,7 @@ namespace ix
         inflateEnd(&inflateState);
         return true;
     }
+#endif
 
     void HttpClient::log(const std::string& msg, HttpRequestArgsPtr args)
     {
diff --git a/ixwebsocket/IXHttpClient.h b/ixwebsocket/IXHttpClient.h
index 97727e6e..9e585e7d 100644
--- a/ixwebsocket/IXHttpClient.h
+++ b/ixwebsocket/IXHttpClient.h
@@ -90,7 +90,9 @@ namespace ix
     private:
         void log(const std::string& msg, HttpRequestArgsPtr args);
 
+#ifdef IXWEBSOCKET_USE_ZLIB
         bool gzipInflate(const std::string& in, std::string& out);
+#endif
 
         // Async API background thread runner
         void run();
diff --git a/ixwebsocket/IXHttpServer.cpp b/ixwebsocket/IXHttpServer.cpp
index 4d544f71..08fc3a4c 100644
--- a/ixwebsocket/IXHttpServer.cpp
+++ b/ixwebsocket/IXHttpServer.cpp
@@ -13,7 +13,10 @@
 #include <fstream>
 #include <sstream>
 #include <vector>
+
+#ifdef IXWEBSOCKET_USE_ZLIB
 #include <zlib.h>
+#endif
 
 namespace
 {
@@ -41,6 +44,7 @@ namespace
         return std::make_pair(res.first, std::string(vec.begin(), vec.end()));
     }
 
+#ifdef IXWEBSOCKET_USE_ZLIB
     std::string gzipCompress(const std::string& str)
     {
         z_stream zs; // z_stream is zlib's control structure
@@ -83,6 +87,7 @@ namespace
 
         return outstring;
     }
+#endif
 } // namespace
 
 namespace ix
@@ -168,12 +173,14 @@ namespace ix
 
                 std::string content = res.second;
 
+#ifdef IXWEBSOCKET_USE_ZLIB
                 std::string acceptEncoding = request->headers["Accept-encoding"];
                 if (acceptEncoding == "*" || acceptEncoding.find("gzip") != std::string::npos)
                 {
                     content = gzipCompress(content);
                     headers["Content-Encoding"] = "gzip";
                 }
+#endif
 
                 // Log request
                 std::stringstream ss;
diff --git a/ixwebsocket/IXUserAgent.cpp b/ixwebsocket/IXUserAgent.cpp
index 85fb9992..89dcb0f3 100644
--- a/ixwebsocket/IXUserAgent.cpp
+++ b/ixwebsocket/IXUserAgent.cpp
@@ -8,7 +8,9 @@
 
 #include "IXWebSocketVersion.h"
 #include <sstream>
+#ifdef IXWEBSOCKET_USE_ZLIB
 #include <zlib.h>
+#endif
 
 // Platform name
 #if defined(_WIN32)
@@ -77,8 +79,10 @@ namespace ix
         ss << " nossl";
 #endif
 
+#ifdef IXWEBSOCKET_USE_ZLIB
         // Zlib version
         ss << " zlib " << ZLIB_VERSION;
+#endif
 
         return ss.str();
     }
diff --git a/ixwebsocket/IXWebSocketPerMessageDeflateCodec.cpp b/ixwebsocket/IXWebSocketPerMessageDeflateCodec.cpp
index fb02e755..913b9a04 100644
--- a/ixwebsocket/IXWebSocketPerMessageDeflateCodec.cpp
+++ b/ixwebsocket/IXWebSocketPerMessageDeflateCodec.cpp
@@ -28,21 +28,26 @@ namespace ix
     WebSocketPerMessageDeflateCompressor::WebSocketPerMessageDeflateCompressor()
         : _compressBufferSize(kBufferSize)
     {
+#ifdef IXWEBSOCKET_USE_ZLIB
         memset(&_deflateState, 0, sizeof(_deflateState));
 
         _deflateState.zalloc = Z_NULL;
         _deflateState.zfree = Z_NULL;
         _deflateState.opaque = Z_NULL;
+#endif
     }
 
     WebSocketPerMessageDeflateCompressor::~WebSocketPerMessageDeflateCompressor()
     {
+#ifdef IXWEBSOCKET_USE_ZLIB
         deflateEnd(&_deflateState);
+#endif
     }
 
     bool WebSocketPerMessageDeflateCompressor::init(uint8_t deflateBits,
                                                     bool clientNoContextTakeOver)
     {
+#ifdef IXWEBSOCKET_USE_ZLIB
         int ret = deflateInit2(&_deflateState,
                                Z_DEFAULT_COMPRESSION,
                                Z_DEFLATED,
@@ -57,6 +62,9 @@ namespace ix
         _flush = (clientNoContextTakeOver) ? Z_FULL_FLUSH : Z_SYNC_FLUSH;
 
         return true;
+#else
+        return false;
+#endif
     }
 
     template<typename T>
@@ -96,6 +104,7 @@ namespace ix
     template<typename T, typename S>
     bool WebSocketPerMessageDeflateCompressor::compressData(const T& in, S& out)
     {
+#ifdef IXWEBSOCKET_USE_ZLIB
         //
         // 7.2.1.  Compression
         //
@@ -152,6 +161,9 @@ namespace ix
         }
 
         return true;
+#else
+        return false;
+#endif
     }
 
     //
@@ -160,6 +172,7 @@ namespace ix
     WebSocketPerMessageDeflateDecompressor::WebSocketPerMessageDeflateDecompressor()
         : _compressBufferSize(kBufferSize)
     {
+#ifdef IXWEBSOCKET_USE_ZLIB
         memset(&_inflateState, 0, sizeof(_inflateState));
 
         _inflateState.zalloc = Z_NULL;
@@ -167,16 +180,20 @@ namespace ix
         _inflateState.opaque = Z_NULL;
         _inflateState.avail_in = 0;
         _inflateState.next_in = Z_NULL;
+#endif
     }
 
     WebSocketPerMessageDeflateDecompressor::~WebSocketPerMessageDeflateDecompressor()
     {
+#ifdef IXWEBSOCKET_USE_ZLIB
         inflateEnd(&_inflateState);
+#endif
     }
 
     bool WebSocketPerMessageDeflateDecompressor::init(uint8_t inflateBits,
                                                       bool clientNoContextTakeOver)
     {
+#ifdef IXWEBSOCKET_USE_ZLIB
         int ret = inflateInit2(&_inflateState, -1 * inflateBits);
 
         if (ret != Z_OK) return false;
@@ -186,10 +203,14 @@ namespace ix
         _flush = (clientNoContextTakeOver) ? Z_FULL_FLUSH : Z_SYNC_FLUSH;
 
         return true;
+#else
+        return false;
+#endif
     }
 
     bool WebSocketPerMessageDeflateDecompressor::decompress(const std::string& in, std::string& out)
     {
+#ifdef IXWEBSOCKET_USE_ZLIB
         //
         // 7.2.2.  Decompression
         //
@@ -226,5 +247,8 @@ namespace ix
         } while (_inflateState.avail_out == 0);
 
         return true;
+#else
+        return false;
+#endif
     }
 } // namespace ix
diff --git a/ixwebsocket/IXWebSocketPerMessageDeflateCodec.h b/ixwebsocket/IXWebSocketPerMessageDeflateCodec.h
index 476d3c79..89673f48 100644
--- a/ixwebsocket/IXWebSocketPerMessageDeflateCodec.h
+++ b/ixwebsocket/IXWebSocketPerMessageDeflateCodec.h
@@ -6,7 +6,9 @@
 
 #pragma once
 
+#ifdef IXWEBSOCKET_USE_ZLIB
 #include "zlib.h"
+#endif
 #include <memory>
 #include <string>
 #include <vector>
@@ -34,7 +36,10 @@ namespace ix
         int _flush;
         size_t _compressBufferSize;
         std::unique_ptr<unsigned char[]> _compressBuffer;
+
+#ifdef IXWEBSOCKET_USE_ZLIB
         z_stream _deflateState;
+#endif
     };
 
     class WebSocketPerMessageDeflateDecompressor
@@ -50,7 +55,10 @@ namespace ix
         int _flush;
         size_t _compressBufferSize;
         std::unique_ptr<unsigned char[]> _compressBuffer;
+
+#ifdef IXWEBSOCKET_USE_ZLIB
         z_stream _inflateState;
+#endif
     };
 
 } // namespace ix
diff --git a/ixwebsocket/IXWebSocketPerMessageDeflateOptions.cpp b/ixwebsocket/IXWebSocketPerMessageDeflateOptions.cpp
index da81693a..259ddcba 100644
--- a/ixwebsocket/IXWebSocketPerMessageDeflateOptions.cpp
+++ b/ixwebsocket/IXWebSocketPerMessageDeflateOptions.cpp
@@ -61,6 +61,7 @@ namespace ix
         _clientMaxWindowBits = kDefaultClientMaxWindowBits;
         _serverMaxWindowBits = kDefaultServerMaxWindowBits;
 
+#ifdef IXWEBSOCKET_USE_ZLIB
         // Split by ;
         std::string token;
         std::stringstream tokenStream(extension);
@@ -112,6 +113,7 @@ namespace ix
                 sanitizeClientMaxWindowBits();
             }
         }
+#endif
     }
 
     void WebSocketPerMessageDeflateOptions::sanitizeClientMaxWindowBits()
@@ -126,6 +128,7 @@ namespace ix
 
     std::string WebSocketPerMessageDeflateOptions::generateHeader()
     {
+#ifdef IXWEBSOCKET_USE_ZLIB
         std::stringstream ss;
         ss << "Sec-WebSocket-Extensions: permessage-deflate";
 
@@ -138,11 +141,18 @@ namespace ix
         ss << "\r\n";
 
         return ss.str();
+#else
+        return std::string();
+#endif
     }
 
     bool WebSocketPerMessageDeflateOptions::enabled() const
     {
+#ifdef IXWEBSOCKET_USE_ZLIB
         return _enabled;
+#else
+        return false;
+#endif
     }
 
     bool WebSocketPerMessageDeflateOptions::getClientNoContextTakeover() const
diff --git a/ixwebsocket/IXWebSocketVersion.h b/ixwebsocket/IXWebSocketVersion.h
index d704a633..a2b86a11 100644
--- a/ixwebsocket/IXWebSocketVersion.h
+++ b/ixwebsocket/IXWebSocketVersion.h
@@ -6,4 +6,4 @@
 
 #pragma once
 
-#define IX_WEBSOCKET_VERSION "10.1.1"
+#define IX_WEBSOCKET_VERSION "10.1.2"