diff --git a/CMakeLists.txt b/CMakeLists.txt
index a7559c7..d04353e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -55,7 +55,10 @@ if (${IS_GNU} OR ${IS_CLANG})
             add_definitions(-D_GLIBCXX_PARALLEL)
         endif()
     endif()
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstrict-enums -pipe -fstack-protector-strong -fstack-clash-protection -funwind-tables -fasynchronous-unwind-tables -frtti -fexceptions")
+    if (NOT DEFINED EMSCRIPTEN)
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstack-protector-strong -fstack-clash-protection")
+    endif()
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstrict-enums -pipe -funwind-tables -fasynchronous-unwind-tables -frtti -fexceptions")
     set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -ffunction-sections -fdata-sections -fmerge-all-constants -ftree-vectorize -fno-math-errno")
     include(CheckCXXCompilerFlag)
     set(CF_PROTECTION "-fcf-protection")
@@ -84,7 +87,10 @@ elseif(${IS_CLANG})
         message(FATAL_ERROR "Clang ${MINIMAL_CLANG} or higher is required.")
     endif()
     if (${CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE} OR MINGW) # CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE is false on llvm-mingw toolchains even though it is supported
-        set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -flto=full -fwhole-program-vtables")
+        set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -flto=full")
+        if (NOT DEFINED EMSCRIPTEN)
+            set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fwhole-program-vtables")
+        endif()
     endif()
     set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fstrict-vtable-pointers")
 elseif(MSVC)