diff --git a/cmake/CXXhelpers.cmake b/cmake/CXXhelpers.cmake
index 2263254..68f181e 100644
--- a/cmake/CXXhelpers.cmake
+++ b/cmake/CXXhelpers.cmake
@@ -14,7 +14,7 @@ function(_disable_warning flag)
 endfunction()
 
 function(_set_compile_options proj)
-    if (WIN32)
+    if(MSVC)
         target_compile_options(${proj} PRIVATE /arch:AVX /Zi )
     endif()
 endfunction()
diff --git a/src/FlacDependencies.c b/src/FlacDependencies.c
index e0e7378..58ee094 100644
--- a/src/FlacDependencies.c
+++ b/src/FlacDependencies.c
@@ -79,7 +79,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "FLAC/all.h"
 
-#if defined(_MSC_VER)
+#if defined(_WIN32) || defined(_WIN64)
 #include "FLAC/src/win_utf8_io.c"
 #endif