diff --git a/internal/config/config.go b/internal/config/config.go
index d858c1f..a7e8300 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -27,6 +27,10 @@ func Read(path string) (config types.Configuration, err error) {
 			}
 			config.Remotes[i].Auth.AccessToken = string(content)
 		}
+		// On GitLab and GitHub, any non blank username is working
+		if remote.Auth.Username == "" {
+			config.Remotes[i].Auth.Username = "comin"
+		}
 		if remote.Timeout == 0 {
 			config.Remotes[i].Timeout = 300
 		}
diff --git a/internal/config/config_test.go b/internal/config/config_test.go
index 0ffa661..10a5c9c 100644
--- a/internal/config/config_test.go
+++ b/internal/config/config_test.go
@@ -19,6 +19,7 @@ func TestConfig(t *testing.T) {
 				Auth: types.Auth{
 					AccessToken:     "my-secret",
 					AccessTokenPath: "./secret",
+					Username:        "comin",
 				},
 				Timeout: 300,
 			},
@@ -28,6 +29,7 @@ func TestConfig(t *testing.T) {
 				Auth: types.Auth{
 					AccessToken:     "",
 					AccessTokenPath: "",
+					Username:        "comin",
 				},
 				Timeout: 300,
 			},
diff --git a/internal/repository/git.go b/internal/repository/git.go
index 6bed7f4..98b20f9 100644
--- a/internal/repository/git.go
+++ b/internal/repository/git.go
@@ -121,9 +121,7 @@ func fetch(r repository, remote types.Remote) (err error) {
 	// TODO: support several authentication methods
 	if remote.Auth.AccessToken != "" {
 		fetchOptions.Auth = &http.BasicAuth{
-			// On GitLab, any non blank username is
-			// working.
-			Username: "comin",
+			Username: remote.Auth.Username,
 			Password: remote.Auth.AccessToken,
 		}
 	}
diff --git a/internal/types/types.go b/internal/types/types.go
index 91b6a42..7d4b644 100644
--- a/internal/types/types.go
+++ b/internal/types/types.go
@@ -24,6 +24,7 @@ type GitConfig struct {
 type Auth struct {
 	AccessToken     string
 	AccessTokenPath string `yaml:"access_token_path"`
+	Username        string
 }
 
 type Branch struct {
diff --git a/nix/module-options.nix b/nix/module-options.nix
index 8b64af2..94e29af 100644
--- a/nix/module-options.nix
+++ b/nix/module-options.nix
@@ -75,6 +75,15 @@
                       The path of the auth file.
                     '';
                   };
+                  username = mkOption {
+                    type = str;
+                    default = "comin";
+                    description = ''
+                      The username used to authenticate to the Git
+                      remote repository. Note that any non empty
+                      username is valid on GitLab and GitHub.
+                    '';
+                  };
                 };
               };
             };