diff --git a/CMakeLists.txt b/CMakeLists.txt
index e90e56b2a..8987691c0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -86,8 +86,13 @@ else()
 endif()
 
 # Whether to enable SSE
+if(CMAKE_SYSTEM_NAME STREQUAL "Emscripten")
+  set(FCL_TARGET_SUPPORT_X64_SSE OFF)
+else()
+  set(FCL_TARGET_SUPPORT_X64_SSE ON)
+endif()
 set(SSE_FLAGS "")
-option(FCL_USE_X64_SSE "Whether FCL should x64 SSE instructions" ON)
+option(FCL_USE_X64_SSE "Whether FCL should x64 SSE instructions" ${FCL_TARGET_SUPPORT_X64_SSE})
 if(FCL_USE_X64_SSE)
   if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     set(SSE_FLAGS -mfpmath=sse -msse -msse2 -msse3 -mssse3)