diff --git a/ChangeLog.d/fix-cipher-output-size-macros.txt b/ChangeLog.d/fix-cipher-output-size-macros.txt
new file mode 100644
index 0000000..4a4b971
--- /dev/null
+++ b/ChangeLog.d/fix-cipher-output-size-macros.txt
@@ -0,0 +1,4 @@
+Bugfix
+   * Prevent divide by zero if either of PSA_CIPHER_ENCRYPT_OUTPUT_SIZE() or
+     PSA_CIPHER_UPDATE_OUTPUT_SIZE() were called using an asymmetric key type.
+
diff --git a/include/psa/crypto_sizes.h b/include/psa/crypto_sizes.h
index 2811c23..4c67f10 100644
--- a/include/psa/crypto_sizes.h
+++ b/include/psa/crypto_sizes.h
@@ -992,9 +992,10 @@
  */
 #define PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(key_type, alg, input_length)             \
     (alg == PSA_ALG_CBC_PKCS7 ?                                                 \
+     (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ?                            \
      PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type),          \
                               (input_length) + 1) +                             \
-     PSA_CIPHER_IV_LENGTH((key_type), (alg)) :                                  \
+     PSA_CIPHER_IV_LENGTH((key_type), (alg)) : 0) :                             \
      (PSA_ALG_IS_CIPHER(alg) ?                                                  \
       (input_length) + PSA_CIPHER_IV_LENGTH((key_type), (alg)) :                \
      0))
@@ -1073,12 +1074,13 @@
  */
 #define PSA_CIPHER_UPDATE_OUTPUT_SIZE(key_type, alg, input_length)              \
     (PSA_ALG_IS_CIPHER(alg) ?                                                   \
+    (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ?                             \
      (((alg) == PSA_ALG_CBC_PKCS7      ||                                       \
        (alg) == PSA_ALG_CBC_NO_PADDING ||                                       \
        (alg) == PSA_ALG_ECB_NO_PADDING) ?                                       \
       PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type),         \
                                 input_length) :                                 \
-      (input_length)) :                                                         \
+      (input_length)) : 0) :                                                    \
      0)
 
 /** A sufficient output buffer size for psa_cipher_update(), for any of the
diff --git a/tests/suites/test_suite_psa_crypto.data b/tests/suites/test_suite_psa_crypto.data
index 6eca2f7..e3e9a52 100644
--- a/tests/suites/test_suite_psa_crypto.data
+++ b/tests/suites/test_suite_psa_crypto.data
@@ -1486,6 +1486,18 @@
 PSA cipher: bad order function calls
 cipher_bad_order:
 
+PSA cipher: incorrect key type (HMAC)
+depends_on:PSA_WANT_ALG_HMAC:PSA_WANT_ALG_SHA_256
+cipher_bad_key:PSA_ALG_HMAC(PSA_ALG_SHA_256):PSA_KEY_TYPE_HMAC:"000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f"
+
+PSA cipher: incorrect key type (RSA)
+depends_on:PSA_WANT_ALG_RSA_PKCS1V15_SIGN:PSA_WANT_KEY_TYPE_RSA_KEY_PAIR
+cipher_bad_key:PSA_ALG_RSA_PKCS1V15_SIGN_RAW:PSA_KEY_TYPE_RSA_KEY_PAIR:"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"
+
+PSA cipher: incorrect key type (ECC Family Sep R1)
+depends_on:PSA_WANT_ALG_ECDSA:PSA_WANT_KEY_TYPE_ECC_KEY_PAIR:MBEDTLS_PK_PARSE_C:PSA_WANT_ECC_SECP_R1_256
+cipher_bad_key:PSA_ALG_ECDSA_ANY:PSA_KEY_TYPE_ECC_PUBLIC_KEY(PSA_ECC_FAMILY_SECP_R1):"04dea5e45d0ea37fc566232a508f4ad20ea13d47e4bf5fa4d54a57a0ba012042087097496efc583fed8b24a5b9be9a51de063f5a00a8b698a16fd7f29b5485f320"
+
 PSA cipher encrypt: without initialization
 depends_on:PSA_WANT_ALG_ECB_NO_PADDING:PSA_WANT_KEY_TYPE_AES
 cipher_encrypt_fail:PSA_ALG_ECB_NO_PADDING:PSA_KEY_TYPE_AES:"":"":PSA_ERROR_BAD_STATE
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 9136cb9..150a3f4 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -2560,6 +2560,46 @@
 /* END_CASE */
 
 /* BEGIN_CASE */
+void cipher_bad_key( int alg_arg, int key_type_arg, data_t *key_data )
+{
+    mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT;
+    psa_algorithm_t alg = alg_arg;
+    psa_key_type_t key_type = key_type_arg;
+    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+    psa_cipher_operation_t operation = PSA_CIPHER_OPERATION_INIT;
+    psa_status_t status;
+
+    PSA_ASSERT( psa_crypto_init( ) );
+
+    psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_ENCRYPT );
+    psa_set_key_algorithm( &attributes, alg );
+    psa_set_key_type( &attributes, key_type );
+
+    /* Usage of either of these two size macros would cause divide by zero
+     * with incorrect key types previously. Input length should be irrelevant
+     * here. */
+    TEST_EQUAL( PSA_CIPHER_ENCRYPT_OUTPUT_SIZE( key_type, alg, 16 ),
+                0 );
+    TEST_EQUAL( PSA_CIPHER_UPDATE_OUTPUT_SIZE( key_type, alg, 16 ), 0 );
+
+
+    PSA_ASSERT( psa_import_key( &attributes, key_data->x, key_data->len,
+                                &key ) );
+
+    /* Should fail due to invalid alg type (to support invalid key type).
+     * Encrypt or decrypt will end up in the same place. */
+    status = psa_cipher_encrypt_setup( &operation, key, alg );
+
+    TEST_EQUAL( status, PSA_ERROR_INVALID_ARGUMENT );
+
+exit:
+    psa_cipher_abort( &operation );
+    psa_destroy_key( key );
+    PSA_DONE( );
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
 void cipher_encrypt_validation( int alg_arg,
                                 int key_type_arg,
                                 data_t *key_data,