diff --git a/cmd/cogito/main_test.go b/cmd/cogito/main_test.go
index da6f2a8..e9597e7 100644
--- a/cmd/cogito/main_test.go
+++ b/cmd/cogito/main_test.go
@@ -63,6 +63,10 @@ func TestRunPutSuccess(t *testing.T) {
 	var ghReq github.AddRequest
 	var ghUrl *url.URL
 	gitHubSpy := testhelp.SpyHttpServer(&ghReq, nil, &ghUrl, http.StatusCreated)
+	gitHubSpyURL, err := url.Parse(gitHubSpy.URL)
+	if err != nil {
+		t.Fatalf("error parsing SpyHttpServer URL: %s", err)
+	}
 	var chatMsg googlechat.BasicMessage
 	chatReply := googlechat.MessageReply{}
 	var gchatUrl *url.URL
@@ -72,6 +76,7 @@ func TestRunPutSuccess(t *testing.T) {
 			Owner:        "the-owner",
 			Repo:         "the-repo",
 			AccessToken:  "the-secret",
+			GhHostname:   gitHubSpyURL.Host,
 			GChatWebHook: googleChatSpy.URL,
 			LogLevel:     "debug",
 		},
@@ -80,9 +85,9 @@ func TestRunPutSuccess(t *testing.T) {
 	var out bytes.Buffer
 	var logOut bytes.Buffer
 	inputDir := testhelp.MakeGitRepoFromTestdata(t, "../../cogito/testdata/one-repo/a-repo",
-		testhelp.HttpsRemote("github.com", "the-owner", "the-repo"), "dummySHA", wantGitRef)
+		testhelp.HttpsRemote(gitHubSpyURL.Host, "the-owner", "the-repo"), "dummySHA", wantGitRef)
 
-	err := mainErr(in, &out, &logOut, []string{"out", inputDir})
+	err = mainErr(in, &out, &logOut, []string{"out", inputDir})
 
 	assert.NilError(t, err, "\nout: %s\nlogOut: %s", out.String(), logOut.String())
 	//
diff --git a/cogito/ghcommitsink.go b/cogito/ghcommitsink.go
index 37c7e9d..93091ad 100644
--- a/cogito/ghcommitsink.go
+++ b/cogito/ghcommitsink.go
@@ -41,6 +41,7 @@ func (sink GitHubCommitStatusSink) Send() error {
 	context := ghMakeContext(sink.Request)
 
 	target := &github.Target{
+		Server: "http://" + sink.Request.Source.GhHostname,
 		Retry: retry.Retry{
 			FirstDelay:   retryFirstDelay,
 			BackoffLimit: retryBackoffLimit,
diff --git a/cogito/ghcommitsink_test.go b/cogito/ghcommitsink_test.go
index 5188f68..d74c0fc 100644
--- a/cogito/ghcommitsink_test.go
+++ b/cogito/ghcommitsink_test.go
@@ -23,16 +23,21 @@ func TestSinkGitHubCommitStatusSendSuccess(t *testing.T) {
 	var ghReq github.AddRequest
 	var URL *url.URL
 	ts := testhelp.SpyHttpServer(&ghReq, nil, &URL, http.StatusCreated)
+	gitHubSpyURL, err := url.Parse(ts.URL)
+	if err != nil {
+		t.Fatalf("error parsing SpyHttpServer URL: %s", err)
+	}
 	sink := cogito.GitHubCommitStatusSink{
 		Log:    hclog.NewNullLogger(),
 		GitRef: wantGitRef,
 		Request: cogito.PutRequest{
+			Source: cogito.Source{GhHostname: gitHubSpyURL.Host},
 			Params: cogito.PutParams{State: wantState},
 			Env:    cogito.Environment{BuildJobName: jobName},
 		},
 	}
 
-	err := sink.Send()
+	err = sink.Send()
 
 	assert.NilError(t, err)
 	ts.Close() // Avoid races before the following asserts.
@@ -46,16 +51,21 @@ func TestSinkGitHubCommitStatusSendFailure(t *testing.T) {
 		http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 			w.WriteHeader(http.StatusTeapot)
 		}))
+	gitHubSpyURL, err := url.Parse(ts.URL)
+	if err != nil {
+		t.Fatalf("error parsing SpyHttpServer URL: %s", err)
+	}
 	defer ts.Close()
 	sink := cogito.GitHubCommitStatusSink{
 		Log:    hclog.NewNullLogger(),
 		GitRef: "deadbeefdeadbeef",
 		Request: cogito.PutRequest{
+			Source: cogito.Source{GhHostname: gitHubSpyURL.Host},
 			Params: cogito.PutParams{State: cogito.StatePending},
 		},
 	}
 
-	err := sink.Send()
+	err = sink.Send()
 
 	assert.ErrorContains(t, err,
 		`failed to add state "pending" for commit deadbee: 418 I'm a teapot`)
diff --git a/cogito/protocol.go b/cogito/protocol.go
index ac0b2d9..ab70b33 100644
--- a/cogito/protocol.go
+++ b/cogito/protocol.go
@@ -164,6 +164,7 @@ type Source struct {
 	//
 	// Optional
 	//
+	GhHostname         string       `json:"github_hostname"`
 	GChatWebHook       string       `json:"gchat_webhook"` // SENSITIVE
 	LogLevel           string       `json:"log_level"`
 	LogUrl             string       `json:"log_url"` // DEPRECATED
@@ -179,6 +180,7 @@ func (src Source) String() string {
 
 	fmt.Fprintf(&bld, "owner:                 %s\n", src.Owner)
 	fmt.Fprintf(&bld, "repo:                  %s\n", src.Repo)
+	fmt.Fprintf(&bld, "github_hostname:       %s\n", src.GhHostname)
 	fmt.Fprintf(&bld, "access_token:          %s\n", redact(src.AccessToken))
 	fmt.Fprintf(&bld, "gchat_webhook:         %s\n", redact(src.GChatWebHook))
 	fmt.Fprintf(&bld, "log_level:             %s\n", src.LogLevel)
diff --git a/cogito/protocol_test.go b/cogito/protocol_test.go
index 508910a..4392849 100644
--- a/cogito/protocol_test.go
+++ b/cogito/protocol_test.go
@@ -175,6 +175,7 @@ func TestSourcePrintLogRedaction(t *testing.T) {
 	source := cogito.Source{
 		Owner:              "the-owner",
 		Repo:               "the-repo",
+		GhHostname:         "github.com",
 		AccessToken:        "sensitive-the-access-token",
 		GChatWebHook:       "sensitive-gchat-webhook",
 		LogLevel:           "debug",
@@ -186,6 +187,7 @@ func TestSourcePrintLogRedaction(t *testing.T) {
 	t.Run("fmt.Print redacts fields", func(t *testing.T) {
 		want := `owner:                 the-owner
 repo:                  the-repo
+github_hostname:       github.com
 access_token:          ***REDACTED***
 gchat_webhook:         ***REDACTED***
 log_level:             debug
@@ -205,6 +207,7 @@ sinks: []`
 		}
 		want := `owner:                 the-owner
 repo:                  
+github_hostname:       
 access_token:          
 gchat_webhook:         
 log_level:             
diff --git a/cogito/put_test.go b/cogito/put_test.go
index 3bcac49..294494a 100644
--- a/cogito/put_test.go
+++ b/cogito/put_test.go
@@ -267,7 +267,7 @@ func TestPutterProcessInputDirSuccess(t *testing.T) {
 			"https://github.com/dummy-owner/dummy-repo", "dummySHA", "banana")
 		putter.InputDir = filepath.Join(tmpDir, filepath.Base(tc.inputDir))
 		putter.Request = cogito.PutRequest{
-			Source: cogito.Source{Owner: "dummy-owner", Repo: "dummy-repo", Sinks: tc.sink},
+			Source: cogito.Source{GhHostname: "github.com", Owner: "dummy-owner", Repo: "dummy-repo", Sinks: tc.sink},
 			Params: tc.params,
 		}
 
@@ -319,7 +319,7 @@ func TestPutterProcessInputDirFailure(t *testing.T) {
 			"https://github.com/dummy-owner/dummy-repo", "dummySHA", "banana mango")
 		putter := cogito.NewPutter(hclog.NewNullLogger())
 		putter.Request = cogito.PutRequest{
-			Source: cogito.Source{Owner: "dummy-owner", Repo: "dummy-repo"},
+			Source: cogito.Source{GhHostname: "github.com", Owner: "dummy-owner", Repo: "dummy-repo"},
 			Params: tc.params,
 		}
 		putter.InputDir = filepath.Join(tmpDir, filepath.Base(tc.inputDir))
diff --git a/cogito/putter.go b/cogito/putter.go
index 406dccc..496f883 100644
--- a/cogito/putter.go
+++ b/cogito/putter.go
@@ -131,7 +131,7 @@ func (putter *ProdPutter) ProcessInputDir() error {
 	case 1:
 		repoDir := filepath.Join(putter.InputDir, inputDirs.OrderedList()[0])
 		putter.log.Debug("", "inputDirs", inputDirs, "repoDir", repoDir, "msgDir", msgDir)
-		if err := checkGitRepoDir(repoDir, source.Owner, source.Repo); err != nil {
+		if err := checkGitRepoDir(repoDir, source.GhHostname, source.Owner, source.Repo); err != nil {
 			return err
 		}
 		putter.gitRef, err = getGitCommit(repoDir)
@@ -237,7 +237,7 @@ func collectInputDirs(dir string) ([]string, error) {
 // - The repo configuration contains a "remote origin" section.
 // - The remote origin url can be parsed following the GitHub conventions.
 // - The result of the parse matches OWNER and REPO.
-func checkGitRepoDir(dir, owner, repo string) error {
+func checkGitRepoDir(dir, hostname, owner, repo string) error {
 	cfg, err := mini.LoadConfiguration(filepath.Join(dir, ".git/config"))
 	if err != nil {
 		return fmt.Errorf("parsing .git/config: %w", err)
@@ -259,7 +259,7 @@ func checkGitRepoDir(dir, owner, repo string) error {
 	if err != nil {
 		return fmt.Errorf(".git/config: remote: %w", err)
 	}
-	left := []string{"github.com", owner, repo}
+	left := []string{hostname, owner, repo}
 	right := []string{gu.URL.Host, gu.Owner, gu.Repo}
 	for i, l := range left {
 		r := right[i]
@@ -272,10 +272,11 @@ Git repository configuration (received as 'inputs:' in this PUT step):
     repo: %s
 
 Cogito SOURCE configuration:
+    hostname: %s
     owner: %s
     repo: %s`,
 				gitUrl, gu.Owner, gu.Repo,
-				owner, repo)
+				hostname, owner, repo)
 		}
 	}
 	return nil
diff --git a/cogito/putter_private_test.go b/cogito/putter_private_test.go
index 0abc373..9570fce 100644
--- a/cogito/putter_private_test.go
+++ b/cogito/putter_private_test.go
@@ -2,6 +2,7 @@ package cogito
 
 import (
 	"errors"
+	"fmt"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -65,6 +66,7 @@ func TestCheckGitRepoDirSuccess(t *testing.T) {
 		repoURL string
 	}
 
+	const wantHostname = "github.com"
 	const wantOwner = "smiling"
 	const wantRepo = "butterfly"
 
@@ -73,7 +75,7 @@ func TestCheckGitRepoDirSuccess(t *testing.T) {
 			"dummySHA", "dummyHead")
 
 		err := checkGitRepoDir(filepath.Join(inputDir, filepath.Base(tc.dir)),
-			wantOwner, wantRepo)
+			wantHostname, wantOwner, wantRepo)
 
 		assert.NilError(t, err)
 	}
@@ -82,22 +84,22 @@ func TestCheckGitRepoDirSuccess(t *testing.T) {
 		{
 			name:    "repo with good SSH remote",
 			dir:     "testdata/one-repo/a-repo",
-			repoURL: testhelp.SshRemote("github.com", wantOwner, wantRepo),
+			repoURL: testhelp.SshRemote(wantHostname, wantOwner, wantRepo),
 		},
 		{
 			name:    "repo with good HTTPS remote",
 			dir:     "testdata/one-repo/a-repo",
-			repoURL: testhelp.HttpsRemote("github.com", wantOwner, wantRepo),
+			repoURL: testhelp.HttpsRemote(wantHostname, wantOwner, wantRepo),
 		},
 		{
 			name:    "repo with good HTTP remote",
 			dir:     "testdata/one-repo/a-repo",
-			repoURL: testhelp.HttpRemote("github.com", wantOwner, wantRepo),
+			repoURL: testhelp.HttpRemote(wantHostname, wantOwner, wantRepo),
 		},
 		{
 			name:    "PR resource but with basic auth in URL (see PR #46)",
 			dir:     "testdata/one-repo/a-repo",
-			repoURL: "https://x-oauth-basic:ghp_XXX@github.com/smiling/butterfly.git",
+			repoURL: fmt.Sprintf("https://x-oauth-basic:ghp_XXX@%s/%s/%s.git", wantHostname, wantOwner, wantRepo),
 		},
 	}
 
@@ -114,6 +116,7 @@ func TestCheckGitRepoDirFailure(t *testing.T) {
 		wantErrWild string // wildcard matching
 	}
 
+	const wantHostname = "github.com"
 	const wantOwner = "smiling"
 	const wantRepo = "butterfly"
 
@@ -122,7 +125,7 @@ func TestCheckGitRepoDirFailure(t *testing.T) {
 			"dummySHA", "dummyHead")
 
 		err := checkGitRepoDir(filepath.Join(inDir, filepath.Base(tc.dir)),
-			wantOwner, wantRepo)
+			wantHostname, wantOwner, wantRepo)
 
 		assert.ErrorContains(t, err, tc.wantErrWild)
 	}
@@ -152,6 +155,7 @@ Git repository configuration (received as 'inputs:' in this PUT step):
     repo: repo-a
 
 Cogito SOURCE configuration:
+    hostname: github.com
     owner: smiling
     repo: butterfly`,
 		},
@@ -167,6 +171,7 @@ Git repository configuration (received as 'inputs:' in this PUT step):
     repo: repo-a
 
 Cogito SOURCE configuration:
+    hostname: github.com
     owner: smiling
     repo: butterfly`,
 		},