diff --git a/lib/bento/runner.rb b/lib/bento/runner.rb
index fdeda596f..b59554dcc 100644
--- a/lib/bento/runner.rb
+++ b/lib/bento/runner.rb
@@ -17,7 +17,7 @@ def initialize(opts)
     @dry_run = opts.dry_run
     @metadata_only = opts.metadata_only
     @debug = opts.debug
-    @only = opts.only
+    @only = opts.only ||= nil
     @except = opts.except
     @mirror = opts.mirror
     @headed = opts.headed ||= false
@@ -87,7 +87,7 @@ def packer_build_cmd(template, _var_file)
     var_files.each do |var_file|
       cmd.insert(5, "-var-file=#{var_file}") if File.exist?(var_file)
     end if var_files
-    cmd.insert(4, "-only=#{only}")
+    cmd.insert(4, "-only=#{only}") if only
     cmd.insert(4, "-except=#{except}") if except
     # Build the command line in the correct order and without spaces as future input for the splat operator.
     cmd.insert(4, "-var cpus=#{cpus}") if cpus
diff --git a/packer_templates/pkr-variables.pkr.hcl b/packer_templates/pkr-variables.pkr.hcl
index 855eeb994..ccde6ce5b 100644
--- a/packer_templates/pkr-variables.pkr.hcl
+++ b/packer_templates/pkr-variables.pkr.hcl
@@ -38,7 +38,6 @@ variable "no_proxy" {
 variable "sources_enabled" {
   type = list(string)
   default = [
-    "source.hyperv-iso.vm",
     "source.parallels-iso.vm",
     "source.qemu.vm",
     "source.virtualbox-iso.vm",