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.
  */
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 8ed9deb..768410c 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -768,7 +768,7 @@
     psa_algorithm_t alg1,
     psa_algorithm_t alg2 )
 {
-    /* Common case: the policy only allows alg. */
+    /* Common case: both sides actually specify the same policy. */
     if( alg1 == alg2 )
         return( alg1 );
     /* If the policies are from the same hash-and-sign family, check
@@ -789,12 +789,12 @@
 static int psa_key_algorithm_permits( psa_algorithm_t policy_alg,
                                       psa_algorithm_t requested_alg )
 {
-    /* Common case: the policy only allows alg. */
+    /* Common case: the policy only allows requested_alg. */
     if( requested_alg == policy_alg )
         return( 1 );
     /* If policy_alg is a hash-and-sign with a wildcard for the hash,
-     * and alg is the same hash-and-sign family with any hash,
-     * then alg is compliant with policy_alg. */
+     * and requested_alg is the same hash-and-sign family with any hash,
+     * then requested_alg is compliant with policy_alg. */
     if( PSA_ALG_IS_HASH_AND_SIGN( requested_alg ) &&
         PSA_ALG_SIGN_GET_HASH( policy_alg ) == PSA_ALG_ANY_HASH )
     {