diff --git a/include/llvm-c/Core.h b/include/llvm-c/Core.h
index 3db6f36b3af..3d1ebc531c8 100644
--- a/include/llvm-c/Core.h
+++ b/include/llvm-c/Core.h
@@ -502,7 +502,7 @@ unsigned LLVMGetMDKindID(const char *Name, unsigned SLen);
  * going through the C API deprecation cycle.
  */
 unsigned LLVMGetEnumAttributeKindForName(const char *Name, size_t SLen);
-unsigned LLVMGetLastEnumAttributeKind();
+unsigned LLVMGetLastEnumAttributeKind(void);
 
 /**
  * Create an enum attribute.
diff --git a/lib/IR/Core.cpp b/lib/IR/Core.cpp
index 1dbdccb794a..380fca8c10f 100644
--- a/lib/IR/Core.cpp
+++ b/lib/IR/Core.cpp
@@ -128,7 +128,7 @@ unsigned LLVMGetEnumAttributeKindForName(const char *Name, size_t SLen) {
   return getAttrKindFromName(StringRef(Name, SLen));
 }
 
-unsigned LLVMGetLastEnumAttributeKind() {
+unsigned LLVMGetLastEnumAttributeKind(void) {
   return Attribute::AttrKind::EndAttrKinds;
 }