diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index 0de4e1f..b3ec54f 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -81,7 +81,7 @@
  *          attacks based on arithmetic relations between different
  *          computations made with the same key, or can escalate harmless
  *          side channels into exploitable ones. Use this function only
- *          if it is necessary to support a protocol for which is has been
+ *          if it is necessary to support a protocol for which it has been
  *          verified that the usage of the key with multiple algorithms
  *          is safe.
  */