diff --git a/crypto/aesgcm-footer.h b/crypto/aesgcm-footer.h
index 981905da..fcbaf17a 100644
--- a/crypto/aesgcm-footer.h
+++ b/crypto/aesgcm-footer.h
@@ -9,7 +9,7 @@
  * administrative block containing the lengths of both) is done in the
  * same way no matter what technique is used for the evaluation, so
  * that's centralised into this file, along with as much of the other
- * functionality as posible.
+ * functionality as possible.
  *
  * This footer file is #included by each implementation, but each one
  * will define its own struct type for the state, so that each alloc