diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index 3b747b2e4..c05597ea7 100644
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -13,7 +13,7 @@ check_cxx_compiler_flag(/GR-                    LIBCXX_HAS_NO_GR_FLAG)
 
 # Check libraries
 check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB)
-check_library_exists(c printf "" LIBCXX_HAS_C_LIB)
+check_library_exists(c fopen "" LIBCXX_HAS_C_LIB)
 check_library_exists(m ccos "" LIBCXX_HAS_M_LIB)
 check_library_exists(rt clock_gettime "" LIBCXX_HAS_RT_LIB)
 check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXX_HAS_GCC_S_LIB)