diff --git a/deps/ReactantExtra/API.cpp b/deps/ReactantExtra/API.cpp
index 39b2341115..e2610cc4e9 100644
--- a/deps/ReactantExtra/API.cpp
+++ b/deps/ReactantExtra/API.cpp
@@ -2147,24 +2147,34 @@ REACTANT_ABI int ifrt_client_addressable_device_count(ifrt::Client *client) {
 }
 
 REACTANT_ABI void ifrt_client_devices(ifrt::Client *client,
-                                      ifrt::Device **out_devices) {
+                                      ifrt::Device **out_devices,
+                                      uint64_t num_devices) {
   auto span = client->devices();
+  if (span.size() != num_devices)
+    ReactantThrowError("Incorrect number of devices provided");
+  assert(span.size() == num_devices);
   for (int i = 0; i < span.size(); i++) {
     out_devices[i] = span[i];
   }
 }
 
 REACTANT_ABI void ifrt_client_addressable_devices(ifrt::Client *client,
-                                                  ifrt::Device **out_devices) {
+                                                  ifrt::Device **out_devices,
+                                                  uint64_t num_devices) {
   auto span = client->addressable_devices();
+  if (span.size() != num_devices)
+    ReactantThrowError("Incorrect number of devices provided");
   for (int i = 0; i < span.size(); i++) {
     out_devices[i] = span[i];
   }
 }
 
 REACTANT_ABI void ifrt_client_all_devices(ifrt::Client *client,
-                                          ifrt::Device **out_devices) {
+                                          ifrt::Device **out_devices,
+                                          uint64_t num_devices) {
   auto span = client->GetAllDevices();
+  if (span.size() != num_devices)
+    ReactantThrowError("Incorrect number of devices provided");
   for (int i = 0; i < span.size(); i++) {
     out_devices[i] = span[i];
   }