diff --git a/src/backend/backend.cpp b/src/backend/backend.cpp
index b57b281..262c9e0 100644
--- a/src/backend/backend.cpp
+++ b/src/backend/backend.cpp
@@ -77,10 +77,7 @@ void backend_base_t::free_handler(comp_t handler)
   util::free_handler(handler);
 }
 
-comp_t backend_base_t::alloc_cq()
-{
-  return util::alloc_cq(mpi::config.default_cq_length);
-}
+comp_t backend_base_t::alloc_cq() { return util::alloc_cq(65536); }
 
 void backend_base_t::free_cq(comp_t completion) { util::free_cq(completion); }
 
diff --git a/src/backend/mpi/backend_mpi.cpp b/src/backend/mpi/backend_mpi.cpp
index 86bd013..dc5c76f 100644
--- a/src/backend/mpi/backend_mpi.cpp
+++ b/src/backend/mpi/backend_mpi.cpp
@@ -452,4 +452,9 @@ void backend_mpi_t::barrier(device_t device)
   MPI_SAFECALL(MPI_Barrier(device_p->comm));
 }
 
+comp_t backend_mpi_t::alloc_cq()
+{
+  return util::alloc_cq(mpi::config.default_cq_length);
+}
+
 }  // namespace lcw
\ No newline at end of file
diff --git a/src/backend/mpi/backend_mpi.hpp b/src/backend/mpi/backend_mpi.hpp
index 3afad05..f899c1a 100644
--- a/src/backend/mpi/backend_mpi.hpp
+++ b/src/backend/mpi/backend_mpi.hpp
@@ -38,6 +38,7 @@ class backend_mpi_t : public backend_base_t
            comp_t completion, void* user_context) override;
   tag_t get_max_tag(device_t device) override;
   void barrier(device_t device) override;
+  comp_t alloc_cq() override;
 };
 
 namespace mpi