diff --git a/cmake/ArgumentPassthrough.cmake b/cmake/ArgumentPassthrough.cmake
index b7ba83a..a0367d2 100644
--- a/cmake/ArgumentPassthrough.cmake
+++ b/cmake/ArgumentPassthrough.cmake
@@ -22,7 +22,7 @@ endif()
 if (DEFINED CMAKE_C_COMPILER)
     list(APPEND CMAKE_PASSTHROUGH_ARGS "-DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}")
     list(APPEND CMAKE_PASSTHROUGH_ENV "CC=${CMAKE_C_COMPILER}")
-elseif ($ENV{MSYSTEM} STREQUAL "CLANG64")
+elseif ("$ENV{MSYSTEM}" STREQUAL "CLANG64")
     list(APPEND CMAKE_PASSTHROUGH_ENV "CC=clang")
 endif()
 if (DEFINED CMAKE_C_COMPILER_TARGET)
@@ -31,7 +31,7 @@ endif()
 if (DEFINED CMAKE_CXX_COMPILER)
     list(APPEND CMAKE_PASSTHROUGH_ARGS "-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}")
     list(APPEND CMAKE_PASSTHROUGH_ENV "CXX=${CMAKE_CXX_COMPILER}")
-elseif ($ENV{MSYSTEM} STREQUAL "CLANG64")
+elseif ("$ENV{MSYSTEM}" STREQUAL "CLANG64")
     list(APPEND CMAKE_PASSTHROUGH_ENV "CXX=clang++")
 endif()
 if (DEFINED CMAKE_CXX_COMPILER_TARGET)