diff --git a/command/init_test.go b/command/init_test.go
index 0b86379c7..6a44bc620 100644
--- a/command/init_test.go
+++ b/command/init_test.go
@@ -291,6 +291,32 @@ func TestInitCommand_Run(t *testing.T) {
 				testBuild{want: 1}.fn,
 			},
 		},
+		{
+			"unsupported-non-github-source-address",
+			[]func(t *testing.T, tc testCaseInit){
+				skipInitTestUnlessEnVar(acctest.TestEnvVar).fn,
+			},
+			testMetaFile(t),
+			nil,
+			"h1:47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=",
+			map[string]string{
+				`cfg.pkr.hcl`: `
+					packer {
+						required_plugins {
+							comment = {
+								source  = "example.com/sylviamoss/comment"
+								version = "v0.2.19"
+							}
+						}
+					}`,
+			},
+			cfg.dir("6_pkr_config"),
+			cfg.dir("6_pkr_user_folder"),
+			1,
+			nil,
+			"h1:47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=",
+			nil,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
diff --git a/packer/plugin-getter/github/getter.go b/packer/plugin-getter/github/getter.go
index c34e092a8..c33c55d77 100644
--- a/packer/plugin-getter/github/getter.go
+++ b/packer/plugin-getter/github/getter.go
@@ -23,6 +23,7 @@ import (
 const (
 	ghTokenAccessor  = "PACKER_GITHUB_API_TOKEN"
 	defaultUserAgent = "packer-plugin-getter"
+	defaultHostname  = "github.com"
 )
 
 type Getter struct {
@@ -154,6 +155,11 @@ func (t *HostSpecificTokenAuthTransport) base() http.RoundTripper {
 }
 
 func (g *Getter) Get(what string, opts plugingetter.GetOptions) (io.ReadCloser, error) {
+	if opts.PluginRequirement.Identifier.Hostname != defaultHostname {
+		s := opts.PluginRequirement.Identifier.String() + " doesn't appear to be a valid " + defaultHostname + " source address; check source and try again."
+		return nil, errors.New(s)
+	}
+
 	ctx := context.TODO()
 	if g.Client == nil {
 		var tc *http.Client
diff --git a/packer/plugin-getter/plugins.go b/packer/plugin-getter/plugins.go
index 9dd670741..9595b67a0 100644
--- a/packer/plugin-getter/plugins.go
+++ b/packer/plugin-getter/plugins.go
@@ -345,7 +345,7 @@ func (pr *Requirement) InstallLatest(opts InstallOptions) (*Installation, error)
 	getters := opts.Getters
 	fail := fmt.Errorf("could not find a local nor a remote checksum for plugin %q %q", pr.Identifier, pr.VersionConstraints)
 
-	log.Printf("[TRACE] getting available versions for the the %s plugin", pr.Identifier)
+	log.Printf("[TRACE] getting available versions for the %s plugin", pr.Identifier)
 	versions := version.Collection{}
 	for _, getter := range getters {