diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7a13564..96df5ea 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.14)
 
 set(VERSION "0.4.1")
-project(cpuid LANGUAGES C CXX ASM VERSION ${VERSION})
+project(cpuid LANGUAGES C CXX ASM_MASM VERSION ${VERSION})
 
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_C_STANDARD 99)
diff --git a/libcpuid/CMakeLists.txt b/libcpuid/CMakeLists.txt
index 48cadd6..96533ac 100644
--- a/libcpuid/CMakeLists.txt
+++ b/libcpuid/CMakeLists.txt
@@ -1,12 +1,18 @@
+set(cpuid_sources cpuid_main.c
+    recog_intel.c
+    recog_amd.c
+    rdtsc.c
+    libcpuid_util.c
+    rdmsr.c
+    msrdriver.c
+    asm-bits.c)
+
+if ("${MSVC_CXX_ARCHITECTURE_ID}" MATCHES "x64")
+    list(APPEND cpuid_sources masm-x64.asm)
+endif ()
+
 add_library(cpuid
-            cpuid_main.c
-            recog_intel.c
-            recog_amd.c
-            rdtsc.c
-            asm-bits.c
-            libcpuid_util.c
-            rdmsr.c
-            msrdriver.c
+            ${cpuid_sources}
             )
 target_include_directories(cpuid SYSTEM PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>)