diff --git a/libunwind/cmake/config-ix.cmake b/libunwind/cmake/config-ix.cmake
index a36f978e8fbd..32669e0a75b1 100644
--- a/libunwind/cmake/config-ix.cmake
+++ b/libunwind/cmake/config-ix.cmake
@@ -39,7 +39,7 @@ check_cxx_compiler_flag(/EHs-                 LIBUNWIND_HAS_NO_EHS_FLAG)
 check_cxx_compiler_flag(/EHa-                 LIBUNWIND_HAS_NO_EHA_FLAG)
 check_cxx_compiler_flag(/GR-                  LIBUNWIND_HAS_NO_GR_FLAG)
 
-check_library_exists(c printf "" LIBUNWIND_HAS_C_LIB)
+check_library_exists(c fopen "" LIBUNWIND_HAS_C_LIB)
 check_library_exists(dl dladdr "" LIBUNWIND_HAS_DL_LIB)
 check_library_exists(pthread pthread_once "" LIBUNWIND_HAS_PTHREAD_LIB)