diff --git a/CMakeModules/Environment.cmake b/CMakeModules/Environment.cmake
index 069d4f8..b565049 100644
--- a/CMakeModules/Environment.cmake
+++ b/CMakeModules/Environment.cmake
@@ -21,26 +21,11 @@ get_filename_component(_CHROMIUM_PYTHONPATH
                        "${CMAKE_SOURCE_DIR}/build"
                        REALPATH)
 
-if (WIN32)
-  set(PREFIX_FILENAME ${CMAKE_BINARY_DIR}/prefix.bat)
-  set(PREFIX_COMMAND set)
-  set(PREFIX_HEADER "@ECHO OFF")
-  set(PREFIX_EVAL "%*")
-  set(PREFIX_EXECUTE cmd /c ${PREFIX_FILENAME})
-else (WIN32)
-  set(PREFIX_FILENAME ${CMAKE_BINARY_DIR}/prefix.sh)
-  set(PREFIX_COMMAND export)
-  set(PREFIX_HEADER "")
-  set(PREFIX_EVAL eval\ $@)
-  set(PREFIX_EXECUTE /bin/sh ${PREFIX_FILENAME})
-endif (WIN32)
-
-file(WRITE ${PREFIX_FILENAME} "${PREFIX_HEADER}
-${PREFIX_COMMAND} PATH=${_WEBRTC_PATH}
-${PREFIX_COMMAND} PYTHONPATH=${_CHROMIUM_PYTHONPATH}
-${PREFIX_COMMAND} DEPOT_TOOLS_WIN_TOOLCHAIN=0
-${PREFIX_COMMAND} DEPOT_TOOLS_UPDATE=0
-${PREFIX_COMMAND} CHROME_HEADLESS=1
-${PREFIX_EVAL}
-")
+set(_WEBRTC_ENV
+    PATH=\"${_WEBRTC_PATH}\"
+    PYTHONPATH=\"${_CHROMIUM_PYTHONPATH}\"
+    DEPOT_TOOLS_WIN_TOOLCHAIN=0
+    DEPOT_TOOLS_UPDATE=0
+    CHROME_HEADLESS=1)
 
+set(PREFIX_EXECUTE cmake -E env ${_WEBRTC_ENV} ${PREFIX_FILENAME})
diff --git a/CMakeModules/Gn.cmake b/CMakeModules/Gn.cmake
index dfbe09e..73aab6e 100644
--- a/CMakeModules/Gn.cmake
+++ b/CMakeModules/Gn.cmake
@@ -1,24 +1,24 @@
-set(_GEN_ARGS "use_gold=false target_cpu=\\\"${TARGET_CPU}\\\" target_os=\\\"${TARGET_OS}\\\"")
+set(_GEN_ARGS use_gold=false target_cpu=\\"${TARGET_CPU}\\" target_os=\\"${TARGET_OS}\\")
 
 if (MSVC OR XCODE)
   set(_GEN_ARGS ${_GEN_ARGS} is_debug=$<$<CONFIG:Debug>:true>$<$<CONFIG:Release>:false>$<$<CONFIG:RelWithDebInfo>:false>$<$<CONFIG:MinSizeRel>:false>)
   set(_NINJA_BUILD_DIR out/$<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>$<$<CONFIG:RelWithDebInfo>:Release>$<$<CONFIG:MinSizeRel>:Release>)
 elseif (CMAKE_BUILD_TYPE MATCHES Debug)
-  set(_GEN_ARGS "${_GEN_ARGS} is_debug=true")
+  set(_GEN_ARGS ${_GEN_ARGS} is_debug=true)
   set(_NINJA_BUILD_DIR out/Debug)
 else (MSVC OR XCODE)
-  set(_GEN_ARGS "${_GEN_ARGS} is_debug=false")
+  set(_GEN_ARGS ${_GEN_ARGS} is_debug=false)
   set(_NINJA_BUILD_DIR out/Release)
 endif (MSVC OR XCODE)
 
 if (BUILD_TESTS)
-  set(_GEN_ARGS "${_GEN_ARGS} rtc_include_tests=true")
+  set(_GEN_ARGS ${_GEN_ARGS} rtc_include_tests=true)
 else (BUILD_TESTS)
-  set(_GEN_ARGS "${_GEN_ARGS} rtc_include_tests=false")
+  set(_GEN_ARGS ${_GEN_ARGS} rtc_include_tests=false)
 endif (BUILD_TESTS)
 
 if (GN_EXTRA_ARGS)
-  set(_GEN_ARGS "${_GEN_ARGS} ${GN_EXTRA_ARGS}")
+  set(_GEN_ARGS ${_GEN_ARGS} ${GN_EXTRA_ARGS})
 endif (GN_EXTRA_ARGS)
 
 set(_GEN_COMMAND gn gen ${_NINJA_BUILD_DIR} --args=\"${_GEN_ARGS}\")