diff --git a/llvm/include/llvm/Demangle/DemangleConfig.h b/llvm/include/llvm/Demangle/DemangleConfig.h
index 7ee23a4546377..912c9b869bf7d 100644
--- a/llvm/include/llvm/Demangle/DemangleConfig.h
+++ b/llvm/include/llvm/Demangle/DemangleConfig.h
@@ -15,6 +15,9 @@
 #ifndef LLVM_DEMANGLE_DEMANGLECONFIG_H
 #define LLVM_DEMANGLE_DEMANGLECONFIG_H
 
+// llvm-config.h is required for LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS
+#include "llvm/Config/llvm-config.h"
+
 #ifndef __has_feature
 #define __has_feature(x) 0
 #endif