diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7ab54c500..44417b100 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -250,6 +250,8 @@ option(FORCE_SSE42 "force building with SSE4.2, even when PORTABLE=ON" OFF)
 option(FORCE_AVX "force building with AVX, even when PORTABLE=ON" OFF)
 option(FORCE_AVX2 "force building with AVX2, even when PORTABLE=ON" OFF)
 if(PORTABLE)
+  add_definitions(-DROCKSDB_PORTABLE)
+
   # MSVC does not need a separate compiler flag to enable SSE4.2; if nmmintrin.h
   # is available, it is available by default.
   if(FORCE_SSE42 AND NOT MSVC)
@@ -292,8 +294,7 @@ if(NOT MSVC)
   set(CMAKE_REQUIRED_FLAGS "-msse4.2 -mpclmul")
 endif()
 
-if (NOT PORTABLE OR FORCE_SSE42)
-  CHECK_CXX_SOURCE_COMPILES("
+CHECK_CXX_SOURCE_COMPILES("
 #include <cstdint>
 #include <nmmintrin.h>
 #include <wmmintrin.h>
@@ -305,12 +306,11 @@ int main() {
   auto d = _mm_cvtsi128_si64(c);
 }
 " HAVE_SSE42)
-  if(HAVE_SSE42)
-    add_definitions(-DHAVE_SSE42)
-    add_definitions(-DHAVE_PCLMUL)
-  elseif(FORCE_SSE42)
-    message(FATAL_ERROR "FORCE_SSE42=ON but unable to compile with SSE4.2 enabled")
-  endif()
+if(HAVE_SSE42)
+  add_definitions(-DHAVE_SSE42)
+  add_definitions(-DHAVE_PCLMUL)
+elseif(FORCE_SSE42)
+  message(FATAL_ERROR "FORCE_SSE42=ON but unable to compile with SSE4.2 enabled")
 endif()
 
 # Check if -latomic is required or not
diff --git a/util/crc32c.cc b/util/crc32c.cc
index 9deaf7fc6..d71c71c2e 100644
--- a/util/crc32c.cc
+++ b/util/crc32c.cc
@@ -1167,7 +1167,7 @@ static inline Function Choose_Extend() {
 #else
   if (isSSE42()) {
     if (isPCLMULQDQ()) {
-#if defined HAVE_SSE42  && defined HAVE_PCLMUL && !defined NO_THREEWAY_CRC32C
+#if (defined HAVE_SSE42 && defined HAVE_PCLMUL) && !defined NO_THREEWAY_CRC32C
       return crc32c_3way;
 #else
     return ExtendImpl<Fast_CRC32>; // Fast_CRC32 will check HAVE_SSE42 itself