diff --git a/OpenVPN Adapter/OpenVPNCertificate.m b/OpenVPN Adapter/OpenVPNCertificate.m
index 05b3582..bfa942c 100644
--- a/OpenVPN Adapter/OpenVPNCertificate.m	
+++ b/OpenVPN Adapter/OpenVPNCertificate.m	
@@ -12,7 +12,7 @@
 
 @interface OpenVPNCertificate ()
 
-@property (nonatomic) mbedtls_x509_crt *crt;
+@property (nonatomic, assign) mbedtls_x509_crt *crt;
 
 @end