diff --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -292,13 +292,19 @@
 /// using the `builder`.  LLVM IR Builder does not have a generic interface so
 /// this has to be a long chain of `if`s calling different functions with a
 /// different number of arguments.
-LogicalResult ModuleTranslation::convertOperation(Operation &opInst,
+LogicalResult ModuleTranslation::convertOperation(Operation &op,
                                                   llvm::IRBuilder<> &builder) {
-  if (succeeded(iface.convertOperation(&opInst, builder, *this)))
+  const LLVMTranslationDialectInterface *opIface = iface.getInterfaceFor(&op);
+  if (!opIface)
+    return op.emitError("cannot be converted to LLVM IR: missing "
+                        "`LLVMTranslationDialectInterface` registration for "
+                        "dialect for op: ")
+           << op.getName();
+
+  if (succeeded(opIface->convertOperation(&op, builder, *this)))
     return success();
-
-  return opInst.emitError("unsupported or non-LLVM operation: ")
-         << opInst.getName();
+  return op.emitError("LLVM Translation failed for operation: ")
+         << op.getName();
 }
 
 /// Convert block to LLVM IR.  Unless `ignoreArguments` is set, emit PHI nodes