diff --git a/libuavcan/test/transport/outgoing_transfer_registry.cpp b/libuavcan/test/transport/outgoing_transfer_registry.cpp
index 50eb67eb9a..393a0abb7f 100644
--- a/libuavcan/test/transport/outgoing_transfer_registry.cpp
+++ b/libuavcan/test/transport/outgoing_transfer_registry.cpp
@@ -12,7 +12,7 @@
 TEST(OutgoingTransferRegistry, Basic)
 {
     using uavcan::OutgoingTransferRegistryKey;
-    uavcan::PoolAllocator<uavcan::MemPoolBlockSize * 4, uavcan::MemPoolBlockSize> poolmgr;
+    uavcan::PoolAllocator<uavcan::MemPoolBlockSize * 2, uavcan::MemPoolBlockSize> poolmgr;
     uavcan::OutgoingTransferRegistry otr(poolmgr);
 
     otr.cleanup(tsMono(1000));