diff --git a/chapter05/firewall5.yaml b/chapter05/firewall5.yaml
index c724a40..bd9c59e 100644
--- a/chapter05/firewall5.yaml
+++ b/chapter05/firewall5.yaml
@@ -48,7 +48,7 @@ Resources:
   SecurityGroupProxy:
     Type: 'AWS::EC2::SecurityGroup'
     Properties:
-      GroupDescription: 'Allowing incoming HTTP and ICPM from anywhere.'
+      GroupDescription: 'Allowing incoming HTTP and ICMP from anywhere.'
       VpcId: !Ref VPC
       SecurityGroupIngress:
       - Description: 'allowing inbound ICMP traffic'
diff --git a/chapter05/vpc.yaml b/chapter05/vpc.yaml
index fe2e231..7e9d5a7 100644
--- a/chapter05/vpc.yaml
+++ b/chapter05/vpc.yaml
@@ -60,13 +60,11 @@ Resources:
     Type: 'AWS::EC2::VPC'
     Properties:
       CidrBlock: '10.0.0.0/16'
-      EnableDnsHostnames: 'true'
       Tags:
       - Key: Name
         Value: 'AWS in Action: chapter 5 (VPC)'
   InternetGateway:
     Type: 'AWS::EC2::InternetGateway'
-    Properties: {}
   VPCGatewayAttachment:
     Type: 'AWS::EC2::VPCGatewayAttachment'
     Properties:
@@ -77,7 +75,6 @@ Resources:
     Properties:
       AvailabilityZone: !Select [0, !GetAZs '']
       CidrBlock: '10.0.0.0/24'
-      MapPublicIpOnLaunch: true
       VpcId: !Ref VPC
       Tags:
       - Key: Name