diff --git a/pkg/apis/extensions/v1beta1/conversion.go b/pkg/apis/extensions/v1beta1/conversion.go
index 04aa3a316e0..70853877ecc 100644
--- a/pkg/apis/extensions/v1beta1/conversion.go
+++ b/pkg/apis/extensions/v1beta1/conversion.go
@@ -338,10 +338,12 @@ func Convert_v1beta1_NetworkPolicyIngressRule_To_networking_NetworkPolicyIngress
 			return err
 		}
 	}
-	out.From = make([]networking.NetworkPolicyPeer, len(in.From))
-	for i := range in.From {
-		if err := Convert_v1beta1_NetworkPolicyPeer_To_networking_NetworkPolicyPeer(&in.From[i], &out.From[i], s); err != nil {
-			return err
+	if in.From != nil {
+		out.From = make([]networking.NetworkPolicyPeer, len(in.From))
+		for i := range in.From {
+			if err := Convert_v1beta1_NetworkPolicyPeer_To_networking_NetworkPolicyPeer(&in.From[i], &out.From[i], s); err != nil {
+				return err
+			}
 		}
 	}
 	return nil
@@ -354,10 +356,12 @@ func Convert_networking_NetworkPolicyIngressRule_To_v1beta1_NetworkPolicyIngress
 			return err
 		}
 	}
-	out.From = make([]extensionsv1beta1.NetworkPolicyPeer, len(in.From))
-	for i := range in.From {
-		if err := Convert_networking_NetworkPolicyPeer_To_v1beta1_NetworkPolicyPeer(&in.From[i], &out.From[i], s); err != nil {
-			return err
+	if in.From != nil {
+		out.From = make([]extensionsv1beta1.NetworkPolicyPeer, len(in.From))
+		for i := range in.From {
+			if err := Convert_networking_NetworkPolicyPeer_To_v1beta1_NetworkPolicyPeer(&in.From[i], &out.From[i], s); err != nil {
+				return err
+			}
 		}
 	}
 	return nil