diff --git a/mlir/lib/Bindings/Python/ExecutionEngineModule.cpp b/mlir/lib/Bindings/Python/ExecutionEngineModule.cpp
--- a/mlir/lib/Bindings/Python/ExecutionEngineModule.cpp
+++ b/mlir/lib/Bindings/Python/ExecutionEngineModule.cpp
@@ -31,12 +31,21 @@
   }
   MlirExecutionEngine get() { return executionEngine; }
 
-  void release() { executionEngine.ptr = nullptr; }
+  void release() {
+    executionEngine.ptr = nullptr;
+    referencedObjects.clear();
+  }
   pybind11::object getCapsule() {
     return py::reinterpret_steal<py::object>(
         mlirPythonExecutionEngineToCapsule(get()));
   }
 
+  // Add an object to the list of referenced objects whose lifetime must exceed
+  // those of the ExecutionEngine.
+  void addReferencedObject(pybind11::object obj) {
+    referencedObjects.push_back(obj);
+  }
+
   static pybind11::object createFromCapsule(pybind11::object capsule) {
     MlirExecutionEngine rawPm =
         mlirPythonCapsuleToExecutionEngine(capsule.ptr());
@@ -47,6 +56,10 @@
 
 private:
   MlirExecutionEngine executionEngine;
+  // We support Python ctypes closures as callbacks. Keep a list of the objects
+  // so that they don't get garbage collected. (The ExecutionEngine itself
+  // just holds raw pointers with no lifetime semantics).
+  std::vector<py::object> referencedObjects;
 };
 
 } // anonymous namespace
@@ -96,13 +109,17 @@
       .def(
           "raw_register_runtime",
           [](PyExecutionEngine &executionEngine, const std::string &name,
-             uintptr_t sym) {
+             py::object callbackObj) {
+            executionEngine.addReferencedObject(callbackObj);
+            uintptr_t rawSym =
+                py::cast<uintptr_t>(py::getattr(callbackObj, "value"));
             mlirExecutionEngineRegisterSymbol(
                 executionEngine.get(),
                 mlirStringRefCreate(name.c_str(), name.size()),
-                reinterpret_cast<void *>(sym));
+                reinterpret_cast<void *>(rawSym));
           },
-          "Lookup function `func` in the ExecutionEngine.")
+          py::arg("name"), py::arg("callback"),
+          "Register `callback` as the runtime symbol `name`.")
       .def(
           "dump_to_object_file",
           [](PyExecutionEngine &executionEngine, const std::string &fileName) {
diff --git a/mlir/python/mlir/execution_engine.py b/mlir/python/mlir/execution_engine.py
--- a/mlir/python/mlir/execution_engine.py
+++ b/mlir/python/mlir/execution_engine.py
@@ -39,5 +39,5 @@
     under the provided `name`. The `ctypes_callback` must be a
     `CFuncType` that outlives the execution engine.
     """
-    callback = ctypes.cast(ctypes_callback, ctypes.c_void_p).value
+    callback = ctypes.cast(ctypes_callback, ctypes.c_void_p)
     self.raw_register_runtime("_mlir_ciface_" + name, callback)