diff --git a/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-cbc.txt b/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-cbc.txt
index 173b074..f425abb 100644
--- a/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-cbc.txt
+++ b/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-cbc.txt
@@ -1,5 +1,6 @@
 # CAST5 CBC vectors built for https://github.com/pyca/cryptography
 # Derived from the AESVS MMT test data for CBC
+# Verified against the CommonCrypto and Go crypto packages
 # Key Length : 128
 
 COUNT = 0
diff --git a/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-cfb.txt b/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-cfb.txt
index d1a810d..165414e 100644
--- a/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-cfb.txt
+++ b/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-cfb.txt
@@ -1,5 +1,6 @@
 # CAST5 CBC vectors built for https://github.com/pyca/cryptography
 # Derived from the AESVS MMT test data for CFB128
+# Verified against the CommonCrypto and Go crypto packages
 # Key Length : 128
 
 COUNT = 0
diff --git a/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-ofb.txt b/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-ofb.txt
index 7ec42f7..0fe447b 100644
--- a/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-ofb.txt
+++ b/tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-ofb.txt
@@ -1,5 +1,6 @@
 # CAST5 CBC vectors built for https://github.com/pyca/cryptography
 # Derived from the AESVS MMT test data for OFB
+# Verified against the CommonCrypto and Go crypto packages
 # Key Length : 128
 
 COUNT = 0