diff --git a/motors/peripheral/uart.cc b/motors/peripheral/uart.cc
index 6e48320..0617e3f 100644
--- a/motors/peripheral/uart.cc
+++ b/motors/peripheral/uart.cc
@@ -70,7 +70,7 @@
   // otherwise reading S1) before the final one. In practice, the FIFOs are so
   // short on this part it probably won't help anything.
   aos::SizedArray<char, 4> result;
-  while (DataAvailable() && !result.full()) {
+  while (DataAvailable() && result.size() != result.capacity()) {
     result.push_back(ReadCharacter());
   }
   return result;