Fix grammar.
diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index f6211a8..9d141b2 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -414,7 +414,7 @@
  * Closing the key handle makes the handle invalid, and the key handle
  * must not be used again by the application.
  *
- * \note If the key handle was used to setup an active
+ * \note If the key handle was used to set up an active
  * :ref:\`multipart operation <multipart-operations>\`, then closing the
  * key handle can cause the multipart operation to fail. Applications should
  * maintain the key handle until after the multipart operation has finished.