diff --git a/Source/MOLCertificate/MOLCertificate.m b/Source/MOLCertificate/MOLCertificate.m
index 3d75512..0a80fce 100644
--- a/Source/MOLCertificate/MOLCertificate.m
+++ b/Source/MOLCertificate/MOLCertificate.m
@@ -29,6 +29,7 @@ @implementation MOLCertificate
 #pragma mark Init/Dealloc
 
 - (instancetype)initWithSecCertificateRef:(SecCertificateRef)certRef {
+  if (!certRef) return nil;
   self = [super init];
   if (self) {
     _certRef = certRef;