diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index ac2bec97b..0ff6d4426 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -2,7 +2,7 @@ on: [push, pull_request]
 name: Build
 jobs:
   build-linux:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - run: sudo apt install -y valgrind uuid-dev
       - uses: actions/checkout@v2
@@ -161,7 +161,7 @@ jobs:
           name: lib3mf_sdk.zip
           path: build/lib3mf_sdk.zip
   deploy-linux:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     needs: [assemble-sdk]
     steps:
       - run: sudo apt install -y zip unzip
@@ -213,7 +213,7 @@ jobs:
           cmake --build . --config Release
           ./Release/Example_ExtractInfo.exe ../../Files/Helix.3mf
   deploy-macos:
-    runs-on: macos-10.15
+    runs-on: macos-11
     needs: [assemble-sdk]
     steps:
       - name: Download lib3mf_sdk artifact
diff --git a/CMakeLists.txt b/CMakeLists.txt
index e366f3f3b..411e33aec 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -129,7 +129,6 @@ target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/I
 target_include_directories(${PROJECT_NAME} PRIVATE ${LIBS_INCLUDE})
 
 if (USE_INCLUDED_LIBZIP)
-    target_compile_options(${PROJECT_NAME} PRIVATE "-DZIP_STATIC")
     target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/Libraries/libzip/Include)
     if(MSVC)
       target_compile_definitions(${PROJECT_NAME} PRIVATE _CRT_SECURE_NO_WARNINGS)
@@ -146,7 +145,7 @@ if (USE_INCLUDED_LIBZIP)
             "-DZLIB_LIBRARY=zlibstatic" "-DENABLE_COMMONCRYPTO=OFF" "-DENABLE_GNUTLS=OFF" "-DENABLE_MBEDTLS=OFF" 
             "-DENABLE_OPENSSL=OFF" "-DENABLE_WINDOWS_CRYPTO=OFF" 
             "-DENABLE_BZIP2=OFF" "-DENABLE_LZMA=OFF" "-DENABLE_ZSTD=OFF"
-            "-DENABLE_FDOPEN=OFF" "-DBUILD_TOOLS=OFF" "-DBUILD_REGRESS=OFF"
+            "-DBUILD_TOOLS=OFF" "-DBUILD_REGRESS=OFF"
             "-DBUILD_EXAMPLES=OFF" "-DBUILD_DOC=OFF" "-DBUILD_SHARED_LIBS=OFF" "-DLIBZIP_DO_INSTALL=OFF"
             "-S" "${CMAKE_CURRENT_SOURCE_DIR}/submodules/libzip" "-B" "${CMAKE_CURRENT_BINARY_DIR}/libzip"   
       RESULT_VARIABLE CMD_ERROR