diff --git a/mlir/lib/ExecutionEngine/ExecutionEngine.cpp b/mlir/lib/ExecutionEngine/ExecutionEngine.cpp
--- a/mlir/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/mlir/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -294,8 +294,21 @@
 
 Expected<void (*)(void **)> ExecutionEngine::lookup(StringRef name) const {
   auto expectedSymbol = jit->lookup(makePackedFunctionName(name));
-  if (!expectedSymbol)
-    return expectedSymbol.takeError();
+
+  // JIT lookup may return an Error referring to strings stored internally by
+  // the JIT. If the Error outlives the ExecutionEngine, it would want have a
+  // dangling reference, which is currently caught by an assertion inside JIT
+  // thanks to hand-rolled reference counting. Rewrap the error message into a
+  // string before returning. Alternatively, ORC JIT should consider copying
+  // the string into the error message.
+  if (!expectedSymbol) {
+    std::string errorMessage;
+    llvm::raw_string_ostream os(errorMessage);
+    llvm::handleAllErrors(expectedSymbol.takeError(),
+                          [&os](llvm::ErrorInfoBase &ei) { ei.log(os); });
+    return make_string_error(os.str());
+  }
+
   auto rawFPtr = expectedSymbol->getAddress();
   auto fptr = reinterpret_cast<void (*)(void **)>(rawFPtr);
   if (!fptr)