diff --git a/cryptography/hazmat/backends/openssl/ssl.py b/cryptography/hazmat/backends/openssl/ssl.py
index 15269bd..89b2c5a 100644
--- a/cryptography/hazmat/backends/openssl/ssl.py
+++ b/cryptography/hazmat/backends/openssl/ssl.py
@@ -17,10 +17,10 @@
 
 TYPES = """
 /* Internally invented symbol to tell us if SSLv2 is supported */
-static const int PYOPENSSL_NO_SSL2;
+static const int CRYPTOGRAPHY_NO_SSL2;
 
 /* Internally invented symbol to tell us if SNI is supported */
-static const int PYOPENSSL_TLSEXT_HOSTNAME;
+static const int CRYPTOGRAPHY_TLSEXT_HOSTNAME;
 
 static const int SSL_FILETYPE_PEM;
 static const int SSL_FILETYPE_ASN1;
@@ -245,18 +245,18 @@
 
 CUSTOMIZATIONS = """
 #ifdef OPENSSL_NO_SSL2
-static const int PYOPENSSL_NO_SSL2 = 1;
+static const int CRYPTOGRAPHY_NO_SSL2 = 1;
 SSL_METHOD* (*SSLv2_method)() = NULL;
 SSL_METHOD* (*SSLv2_client_method)() = NULL;
 SSL_METHOD* (*SSLv2_server_method)() = NULL;
 #else
-static const int PYOPENSSL_NO_SSL2 = 0;
+static const int CRYPTOGRAPHY_NO_SSL2 = 0;
 #endif
 
 #ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
-static const int PYOPENSSL_TLSEXT_HOSTNAME = 1;
+static const int CRYPTOGRAPHY_TLSEXT_HOSTNAME = 1;
 #else
-static const int PYOPENSSL_TLSEXT_HOSTNAME = 0;
+static const int CRYPTOGRAPHY_TLSEXT_HOSTNAME = 0;
 void (*SSL_set_tlsext_host_name)(SSL *, char *) = NULL;
 const char* (*SSL_get_servername)(const SSL *, const int) = NULL;
 void (*SSL_CTX_set_tlsext_servername_callback)(