diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
--- a/llvm/include/llvm-c/Core.h
+++ b/llvm/include/llvm-c/Core.h
@@ -2915,6 +2915,14 @@
  */
 void LLVMGetMDNodeOperands(LLVMValueRef V, LLVMValueRef *Dest);
 
+/**
+ * Replace an operand at a specific index in a llvm::MDNode value.
+ *
+ * @see llvm::MDNode::replaceOperandWith()
+ */
+void LLVMReplaceMDNodeOperandWith(LLVMValueRef V, unsigned Index,
+                                  LLVMMetadataRef Replacement);
+
 /** Deprecated: Use LLVMMDStringInContext2 instead. */
 LLVMValueRef LLVMMDStringInContext(LLVMContextRef C, const char *Str,
                                    unsigned SLen);
diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
--- a/llvm/lib/IR/Core.cpp
+++ b/llvm/lib/IR/Core.cpp
@@ -1248,6 +1248,13 @@
     Dest[i] = getMDNodeOperandImpl(Context, N, i);
 }
 
+void LLVMReplaceMDNodeOperandWith(LLVMValueRef V, unsigned Index,
+                                  LLVMMetadataRef Replacement) {
+  auto *MD = cast<MetadataAsValue>(unwrap(V));
+  auto *N = cast<MDNode>(MD->getMetadata());
+  N->replaceOperandWith(Index, unwrap<Metadata>(Replacement));
+}
+
 unsigned LLVMGetNamedMetadataNumOperands(LLVMModuleRef M, const char *Name) {
   if (NamedMDNode *N = unwrap(M)->getNamedMetadata(Name)) {
     return N->getNumOperands();