diff --git a/moto/ec2/responses/security_groups.py b/moto/ec2/responses/security_groups.py
index ed50c796b..2e821f49b 100644
--- a/moto/ec2/responses/security_groups.py
+++ b/moto/ec2/responses/security_groups.py
@@ -109,7 +109,9 @@ DESCRIBE_SECURITY_GROUPS_RESPONSE = """<DescribeSecurityGroupsResponse xmlns="ht
              <groupId>{{ group.id }}</groupId>
              <groupName>{{ group.name }}</groupName>
              <groupDescription>{{ group.description }}</groupDescription>
-             <vpcId>{{ group.vpc_id or ""}}</vpcId>
+             {% if group.vpc_id %}
+             <vpcId>{{ group.vpc_id }}</vpcId>
+             {% endif %}
              <ipPermissions>
                {% for rule in group.ingress_rules %}
                     <item>