diff --git a/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp b/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp
--- a/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp
+++ b/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp
@@ -266,9 +266,14 @@
     // functions have linkage.
     LLVM::Linkage linkage = LLVM::Linkage::External;
     if (funcOp->hasAttr("llvm.linkage")) {
-      linkage = funcOp->getAttr("llvm.linkage")
-                    .cast<mlir::LLVM::LinkageAttr>()
-                    .getLinkage();
+      auto attr =
+          funcOp->getAttr("llvm.linkage").dyn_cast<mlir::LLVM::LinkageAttr>();
+      if (!attr) {
+        funcOp->emitError()
+            << "Contains llvm.linkage attribute not of type LLVM::LinkageAttr";
+        return nullptr;
+      }
+      linkage = attr.getLinkage();
     }
     auto newFuncOp = rewriter.create<LLVM::LLVMFuncOp>(
         funcOp.getLoc(), funcOp.getName(), llvmType, linkage,
diff --git a/mlir/test/Conversion/StandardToLLVM/convert-funcs.mlir b/mlir/test/Conversion/StandardToLLVM/convert-funcs.mlir
--- a/mlir/test/Conversion/StandardToLLVM/convert-funcs.mlir
+++ b/mlir/test/Conversion/StandardToLLVM/convert-funcs.mlir
@@ -1,4 +1,4 @@
-// RUN: mlir-opt -convert-std-to-llvm %s | FileCheck %s
+// RUN: mlir-opt -convert-std-to-llvm -split-input-file -verify-diagnostics %s | FileCheck %s
 
 //CHECK: llvm.func @second_order_arg(!llvm.ptr<func<void ()>>)
 func private @second_order_arg(%arg0 : () -> ())
@@ -40,6 +40,7 @@
 // CHECK-LABEL: llvm.func extern_weak @llvmlinkage(i32)
 func private @llvmlinkage(i32) attributes { "llvm.linkage" = #llvm.linkage<extern_weak> }
 
+
 // CHECK-LABEL: llvm.func @body(i32)
 func private @body(i32)
 
@@ -62,3 +63,6 @@
   return %0 : i32
 }
 
+// -----
+
+func private @badllvmlinkage(i32) attributes { "llvm.linkage" = 3 : i64 } // expected-error {{Contains llvm.linkage attribute not of type LLVM::LinkageAttr}}