diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index 379b554..4be7adc 100644
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -2,7 +2,7 @@
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 
-check_library_exists(c fopen "" LIBCXXABI_HAS_C_LIB)
+check_library_exists(c __libc_start_main "" LIBCXXABI_HAS_C_LIB)
 if (NOT LIBCXXABI_USE_COMPILER_RT)
   check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXXABI_HAS_GCC_S_LIB)
 endif ()