diff --git a/cryptography/hazmat/backends/openssl/ssl.py b/cryptography/hazmat/backends/openssl/ssl.py
index 32ea219..499e9c3 100644
--- a/cryptography/hazmat/backends/openssl/ssl.py
+++ b/cryptography/hazmat/backends/openssl/ssl.py
@@ -158,11 +158,6 @@
 int SSL_read(SSL *, void *, int);
 X509 *SSL_get_peer_certificate(const SSL *);
 
-/*
- * OpenSSL defines these with STACK_OF(...) but the STACK_OF macro does not
- * play well with cffi.
- */
-
 Cryptography_STACK_OF_X509 *SSL_get_peer_cert_chain(const SSL *);
 Cryptography_STACK_OF_X509_NAME *SSL_get_client_CA_list(const SSL *);
 
@@ -195,9 +190,6 @@
 X509_STORE *SSL_CTX_get_cert_store(const SSL_CTX *);
 int SSL_CTX_add_client_CA(SSL_CTX *, X509 *);
 
-/*
- * See comment above about STACK_OF(...)
- */
 void SSL_CTX_set_client_CA_list(SSL_CTX *, Cryptography_STACK_OF_X509_NAME *);
 
 
diff --git a/cryptography/hazmat/backends/openssl/x509.py b/cryptography/hazmat/backends/openssl/x509.py
index f0c84fd..c83f568 100644
--- a/cryptography/hazmat/backends/openssl/x509.py
+++ b/cryptography/hazmat/backends/openssl/x509.py
@@ -14,6 +14,13 @@
 INCLUDES = """
 #include <openssl/ssl.h>
 
+/*
+ * This is part of a work-around for the difficulty cffi has in dealing with
+ * `STACK_OF(foo)` as the name of a type.  We invent a new, simpler name that
+ * will be an alias for this type and use the alias throughout.  This works
+ * together with another opaque typedef for the same name in the TYPES section.
+ * Note that the result is an opaque type.
+ */
 typedef STACK_OF(X509) Cryptography_STACK_OF_X509;
 """
 
diff --git a/cryptography/hazmat/backends/openssl/x509name.py b/cryptography/hazmat/backends/openssl/x509name.py
index a6f0a3c..bf627d6 100644
--- a/cryptography/hazmat/backends/openssl/x509name.py
+++ b/cryptography/hazmat/backends/openssl/x509name.py
@@ -14,6 +14,9 @@
 INCLUDES = """
 #include <openssl/x509.h>
 
+/*
+ * See the comment above Cryptography_STACK_OF_X509 in x509.py
+ */
 typedef STACK_OF(X509_NAME) Cryptography_STACK_OF_X509_NAME;
 """