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
@@ -1060,9 +1060,13 @@
 LogicalResult ModuleTranslation::convertFunctions() {
   // Convert functions.
   for (auto function : getModuleBody(mlirModule).getOps<LLVMFuncOp>()) {
-    // Ignore external functions.
-    if (function.isExternal())
+    // Do not convert external functions, but do process dialect attributes
+    // attached to them.
+    if (function.isExternal()) {
+      if (failed(convertDialectAttributes(function)))
+        return failure();
       continue;
+    }
 
     if (failed(convertOneFunction(function)))
       return failure();
diff --git a/mlir/test/Target/LLVMIR/external-func-dialect-attr.mlir b/mlir/test/Target/LLVMIR/external-func-dialect-attr.mlir
new file mode 100644
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/external-func-dialect-attr.mlir
@@ -0,0 +1,11 @@
+// RUN: mlir-translate -mlir-to-llvmir %s | FileCheck %s
+
+// Check that dialect attributes are processed for external functions.
+// This might not be an intended use case for `nvvm.minctasm`, but it enables
+// testing this feature easily.
+
+module {
+  llvm.func external @f() attributes { nvvm.minctasm = 10 : i32 }
+  // CHECK: !nvvm.annotations = !{![[NVVM:[0-9]+]]}
+  // CHECK: ![[NVVM]] = !{ptr @f, !"minctasm", i32 10}
+}