diff --git a/CMakeLists.txt b/CMakeLists.txt
index ce60e8daf..015adf4c0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -105,7 +105,7 @@ set(CMAKE_C_STANDARD_REQUIRED ON)
 if(CMAKE_COMPILER_IS_GNUCXX OR CLANG)
   # Note clang-cl is odd and sets both CLANG and MSVC. We base our configuration
   # primarily on our normal Clang one.
-  set(C_CXX_FLAGS "-Werror -Wformat=2 -Wsign-compare -Wwrite-strings -Wvla -Wshadow -Wtype-limits -Wmissing-field-initializers")
+  set(C_CXX_FLAGS "-Wformat=2 -Wsign-compare -Wwrite-strings -Wvla -Wshadow -Wtype-limits -Wmissing-field-initializers")
   if(MSVC)
     # clang-cl sets different default warnings than clang. It also treats -Wall
     # as -Weverything, to match MSVC. Instead -W3 is the alias for -Wall.
@@ -192,12 +192,12 @@ elseif(MSVC)
       )
   string(REPLACE "C" " -wd" MSVC_DISABLED_WARNINGS_STR
                             ${MSVC_DISABLED_WARNINGS_LIST})
-  set(CMAKE_C_FLAGS   "-utf-8 -W4 -WX ${MSVC_DISABLED_WARNINGS_STR}")
+  set(CMAKE_C_FLAGS   "-utf-8 -W4 ${MSVC_DISABLED_WARNINGS_STR}")
   # Without /Zc:__cplusplus, MSVC does not define the right value for
   # __cplusplus. See https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/
   # If this becomes too problematic for downstream code, we can look at
   # _MSVC_LANG.
-  set(CMAKE_CXX_FLAGS "-utf-8 -W4 -WX ${MSVC_DISABLED_WARNINGS_STR} -Zc:__cplusplus")
+  set(CMAKE_CXX_FLAGS "-utf-8 -W4 ${MSVC_DISABLED_WARNINGS_STR} -Zc:__cplusplus")
 endif()
 
 if(WIN32)