diff --git a/core/llvm_config.mk b/core/llvm_config.mk
index 62e51ac..876bc2f 100644
--- a/core/llvm_config.mk
+++ b/core/llvm_config.mk
@@ -15,7 +15,6 @@
 
 CLANG_CONFIG_EXTRA_CFLAGS := \
   -D__compiler_offsetof=__builtin_offsetof \
-  -Dnan=__builtin_nan \
 
 CLANG_CONFIG_UNKNOWN_CFLAGS := \
   -funswitch-loops