diff --git a/clang/include/clang-c/FatalErrorHandler.h b/clang/include/clang-c/FatalErrorHandler.h
index 74c9a8fe98bb..ce8ff2cae735 100644
--- a/clang/include/clang-c/FatalErrorHandler.h
+++ b/clang/include/clang-c/FatalErrorHandler.h
@@ -18,14 +18,14 @@ extern "C" {
  * Installs error handler that prints error message to stderr and calls abort().
  * Replaces currently installed error handler (if any).
  */
-void clang_install_aborting_llvm_fatal_error_handler();
+void clang_install_aborting_llvm_fatal_error_handler(void);
 
 /**
  * Removes currently installed error handler (if any).
  * If no error handler is intalled, the default strategy is to print error
  * message to stderr and call exit(1).
  */
-void clang_uninstall_llvm_fatal_error_handler();
+void clang_uninstall_llvm_fatal_error_handler(void);
 
 #ifdef __cplusplus
 }
diff --git a/clang/tools/libclang/FatalErrorHandler.cpp b/clang/tools/libclang/FatalErrorHandler.cpp
index e9a0d41bab3f..eab17f3dfac7 100644
--- a/clang/tools/libclang/FatalErrorHandler.cpp
+++ b/clang/tools/libclang/FatalErrorHandler.cpp
@@ -18,11 +18,13 @@ static void aborting_fatal_error_handler(void *, const std::string &reason,
   ::abort();
 }
 
-void clang_install_aborting_llvm_fatal_error_handler() {
+extern "C" {
+void clang_install_aborting_llvm_fatal_error_handler(void) {
   llvm::remove_fatal_error_handler();
   llvm::install_fatal_error_handler(aborting_fatal_error_handler, nullptr);
 }
 
-void clang_uninstall_llvm_fatal_error_handler() {
+void clang_uninstall_llvm_fatal_error_handler(void) {
   llvm::remove_fatal_error_handler();
 }
+}
\ No newline at end of file