diff --git a/CMakeLists.txt b/CMakeLists.txt
index af287a4..a0b0599 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -289,7 +289,7 @@ if(ENABLE_ASM)
 		endif()
 	elseif(APPLE AND "${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "x86_64")
 		set(HOST_ASM_MACOSX_X86_64 true)
-	elseif(MSVC AND "${CMAKE_SYSTEM_PROCESSOR}" MATCHES "AMD64")
+	elseif(MSVC AND "${CMAKE_GENERATOR}" MATCHES "Win64")
 		# XXX Disabled for now, CMake's MASM support seems to either never
 		# build supply ASM or build it with the C compiler in a mode where it
 		# does not parse correctly. It might be easier to get NASM support working.
diff --git a/appveyor.yml b/appveyor.yml
index 790db86..8ac2045 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -34,7 +34,7 @@ before_build:
   - bash autogen.sh
   - mkdir build
   - cd build
-  - cmake .. -G "%GENERATOR%" -DBUILD_SHARED_LIBS=%SHARED_LIBS%
+  - cmake .. -G "%GENERATOR%" -DBUILD_SHARED_LIBS=%SHARED_LIBS% -DCMAKE_INSTALL_PREFIX=../local
 
 build_script:
   - cmake --build . --config %CONFIG%
diff --git a/crypto/CMakeLists.txt b/crypto/CMakeLists.txt
index e1b9287..4c902ad 100644
--- a/crypto/CMakeLists.txt
+++ b/crypto/CMakeLists.txt
@@ -920,7 +920,11 @@ endif()
 if(NOT ENABLE_ASM)
 	add_definitions(-DOPENSSL_NO_ASM)
 else()
-	if(WIN32)
+	if(MSVC)
+		if(NOT "${CMAKE_GENERATOR}" MATCHES "Win64")
+			add_definitions(-DOPENSSL_NO_ASM)
+		endif()
+	elseif(WIN32)
 		add_definitions(-DOPENSSL_NO_ASM)
 	endif()
 endif()
diff --git a/update.sh b/update.sh
index 99a293a..d1fe017 100755
--- a/update.sh
+++ b/update.sh
@@ -168,7 +168,12 @@ gen_asm_stdout() {
 	#endif
 	EOF
 	if [ $1 = "masm" ]; then
-		cpp -I./crypto $3.tmp > $3
+		cpp -I./crypto $3.tmp				\
+			| sed -e 's/^#/;/'			\
+			| sed -e 's/|/OR/g'			\
+			| sed -e 's/~/NOT/g'			\
+			| sed -e 's/1 << \([0-9]*\)/1 SHL \1/g'	\
+			> $3
 	else
 		$MV $3.tmp $3
 	fi
@@ -181,7 +186,12 @@ gen_asm() {
 	#endif
 	EOF
 	if [ $1 = "masm" ]; then
-		cpp -I./crypto $3.tmp > $3
+		cpp -I./crypto $3.tmp				\
+			| sed -e 's/^#/;/'			\
+			| sed -e 's/|/OR/g'			\
+			| sed -e 's/~/NOT/g'			\
+			| sed -e 's/1 << \([0-9]*\)/1 SHL \1/g'	\
+			> $3
 	else
 		$MV $3.tmp $3
 	fi