diff --git a/include/freetype/internal/ftcalc.h b/include/freetype/internal/ftcalc.h
index 40634602f..aba9b69a8 100644
--- a/include/freetype/internal/ftcalc.h
+++ b/include/freetype/internal/ftcalc.h
@@ -415,7 +415,7 @@ FT_BEGIN_HEADER
 
 #define FT_MSB( x )  ( 31 - _CountLeadingZeros( x ) )
 
-#elif defined( _M_ARM64 ) || defined( _M_ARM )
+#elif defined( _M_ARM64 ) || defined( _M_ARM ) || defined( _M_ARM64EC )
 
 #include <intrin.h>
 #pragma intrinsic( _CountLeadingZeros )