diff --git a/command/build.go b/command/build.go
index 81e746be5..6636e51da 100644
--- a/command/build.go
+++ b/command/build.go
@@ -301,14 +301,14 @@ Usage: packer build [options] TEMPLATE
 
 Options:
 
-  -color=false                  Disable color output (on by default)
-  -debug                        Debug mode enabled for builds
-  -except=foo,bar,baz           Build all builds other than these
-  -only=foo,bar,baz             Build only the specified builds
-  -force                        Force a build to continue if artifacts exist, deletes existing artifacts
-  -machine-readable             Machine-readable output
-  -on-error=[cleanup|abort|ask] If the build fails do: clean up (default), abort, or ask
-  -parallel=false               Disable parallelization (on by default)
+  -color=false                  Disable color output. (Default: color)
+  -debug                        Debug mode enabled for builds.
+  -except=foo,bar,baz           Build all builds other than these.
+  -only=foo,bar,baz             Build only the specified builds.
+  -force                        Force a build to continue if artifacts exist, deletes existing artifacts.
+  -machine-readable             Produce machine-readable output.
+  -on-error=[cleanup|abort|ask] If the build fails do: clean up (default), abort, or ask.
+  -parallel=false               Disable parallelization. (Default: parallel)
   -timestamp-ui                 Enable prefixing of each ui output with an RFC3339 timestamp.
   -var 'key=value'              Variable for templates, can be used multiple times.
   -var-file=path                JSON file containing user variables.
diff --git a/command/validate.go b/command/validate.go
index f31b106dd..d84cdbc15 100644
--- a/command/validate.go
+++ b/command/validate.go
@@ -180,8 +180,8 @@ Usage: packer validate [options] TEMPLATE
 Options:
 
   -syntax-only           Only check syntax. Do not verify config of the template.
-  -except=foo,bar,baz    Validate all builds other than these
-  -only=foo,bar,baz      Validate only these builds
+  -except=foo,bar,baz    Validate all builds other than these.
+  -only=foo,bar,baz      Validate only these builds.
   -var 'key=value'       Variable for templates, can be used multiple times.
   -var-file=path         JSON file containing user variables.
 `
diff --git a/contrib/zsh-completion/_packer b/contrib/zsh-completion/_packer
index 1e4c4af6b..38df34236 100644
--- a/contrib/zsh-completion/_packer
+++ b/contrib/zsh-completion/_packer
@@ -10,26 +10,28 @@ _packer () {
   )
 
   local -a build_arguments && build_arguments=(
-    '-debug[Debug mode enabled for builds]'
-    '-force[Force a build to continue if artifacts exist, deletes existing artifacts]'
-    '-machine-readable[Machine-readable output]'
-    '-except=[(foo,bar,baz) Build all builds other than these]'
-    '-only=[(foo,bar,baz) Only build the given builds by name]'
-    '-parallel=[(false) Disable parallelization (on by default)]'
+    '-debug[Debug mode enabled for builds.]'
+    '-force[Force a build to continue if artifacts exist, deletes existing artifacts.]'
+    '-machine-readable[Produce machine-readable output.]'
+    '-color=[(false) Disable color output. (Default: color)]'
+    '-except=[(foo,bar,baz) Build all builds other than these.]'
+    '-on-error=[(cleanup,abort,ask) If the build fails do: clean up (default), abort, or ask.]'
+    '-only=[(foo,bar,baz) Only build the given builds by name.]'
+    '-parallel=[(false) Disable parallelization. (Default: parallel)]'
     '-var[("key=value") Variable for templates, can be used multiple times.]'
     '-var-file=[(path) JSON file containing user variables.]'
     '(-)*:files:_files -g "*.json"'
   )
-  
+
   local -a inspect_arguments && inspect_arguments=(
-    '-machine-readable[Machine-readable output]' 
+    '-machine-readable[Machine-readable output]'
     '(-)*:files:_files -g "*.json"'
   )
 
   local -a validate_arguments && validate_arguments=(
     '-syntax-only[Only check syntax. Do not verify config of the template.]'
-    '-except=[(foo,bar,baz) Validate all builds other than these]'
-    '-only=[(foo,bar,baz) Validate only these builds]'
+    '-except=[(foo,bar,baz) Validate all builds other than these].'
+    '-only=[(foo,bar,baz) Validate only these builds].'
     '-var[("key=value") Variable for templates, can be used multiple times.]'
     '-var-file=[(path) JSON file containing user variables.]'
     '(-)*:files:_files -g "*.json"'