diff --git a/CMakeLists.txt b/CMakeLists.txt
index cf1d213..3067481 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,11 +17,6 @@ if (NOT CMAKE_BUILD_TYPE)
     set(CMAKE_BUILD_TYPE Release
         CACHE STRING "Build type (Debug, Release)" FORCE)
 endif ()
-if (NOT (CMAKE_BUILD_TYPE STREQUAL "Debug" OR
-        CMAKE_BUILD_TYPE STREQUAL "Release"))
-    message("${CMAKE_BUILD_TYPE}")
-    message(FATAL_ERROR "CMAKE_BUILD_TYPE must be one of: Debug, Release (current value: '${CMAKE_BUILD_TYPE}')")
-endif ()
 
 set(BUILD_FOR_DISTRIBUTION no
     CACHE BOOL "Building SymEngine for a distribution")
@@ -138,7 +133,7 @@ endif()
 try_compile(HAVE_SYMENGINE_STD_TO_STRING "${CMAKE_CURRENT_BINARY_DIR}/cxx" "${CMAKE_CURRENT_SOURCE_DIR}/cmake/checkstdtostring.cpp"
 	CMAKE_FLAGS "-DCOMPILE_DEFINITIONS=${CMAKE_CXX_FLAGS}")
 
-if ((CMAKE_CXX_COMPILER_ID MATCHES Clang) AND (CMAKE_BUILD_TYPE STREQUAL "Release"))
+if ((CMAKE_CXX_COMPILER_ID MATCHES Clang) AND (NOT(CMAKE_BUILD_TYPE STREQUAL "Debug")))
     try_compile(CHECK_CLANG "${CMAKE_CURRENT_BINARY_DIR}/cxx" "${CMAKE_CURRENT_SOURCE_DIR}/cmake/checkclang.cpp")
     if (NOT ${CHECK_CLANG})
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D__extern_always_inline=inline" )