diff --git a/src/cryptography/hazmat/bindings/commoncrypto/binding.py b/src/cryptography/hazmat/bindings/commoncrypto/binding.py
index 0a284ab..54c7603 100644
--- a/src/cryptography/hazmat/bindings/commoncrypto/binding.py
+++ b/src/cryptography/hazmat/bindings/commoncrypto/binding.py
@@ -48,7 +48,7 @@
         if cls.lib is not None:
             return
 
-        with self._init_lock:
+        with cls._init_lock:
             if cls.lib is None:
                 cls.lib = load_library_for_binding(
                     cls.ffi,
diff --git a/src/cryptography/hazmat/bindings/openssl/binding.py b/src/cryptography/hazmat/bindings/openssl/binding.py
index 7f379f0..5ccee97 100644
--- a/src/cryptography/hazmat/bindings/openssl/binding.py
+++ b/src/cryptography/hazmat/bindings/openssl/binding.py
@@ -118,7 +118,7 @@
         if cls.lib is not None:
             return
 
-        with self._init_lock:
+        with cls._init_lock:
             if cls.lib is None:
                 cls.lib = load_library_for_binding(
                     cls.ffi,