diff --git a/aider/args.py b/aider/args.py
index 08c9bde76..c51781b07 100644
--- a/aider/args.py
+++ b/aider/args.py
@@ -595,9 +595,15 @@ def get_parser(default_config_files, git_root):
         default=None,
     )
     group.add_argument(
-        "--install-main-branch",
-        action="store_true",
-        help="Install the latest version from the main branch",
+        "--install-branch",
+        nargs="?",
+        const=True,
+        metavar="GIT_URL",
+        help=(
+            "Install the latest version from a git branch. If GIT_URL is provided, installs from"
+            " that URL (e.g., git+https://github.com/user/aider.git@my-branch). If no URL is"
+            " provided, installs from the Aider-AI main branch."
+        ),
         default=False,
     )
     group.add_argument(
diff --git a/aider/main.py b/aider/main.py
index ea344f0ba..80258edad 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -34,7 +34,7 @@ from aider.models import ModelSettings
 from aider.onboarding import offer_openrouter_oauth, select_default_model
 from aider.repo import ANY_GIT_ERROR, GitRepo
 from aider.report import report_uncaught_exceptions
-from aider.versioncheck import check_version, install_from_main_branch, install_upgrade
+from aider.versioncheck import check_version, install_from_git_branch, install_upgrade
 from aider.watch import FileWatcher
 
 from .dump import dump  # noqa: F401
@@ -719,9 +719,13 @@ def main(argv=None, input=None, output=None, force_git_root=None, return_coder=F
         analytics.event("exit", reason="Just checking update")
         return 0 if not update_available else 1
 
-    if args.install_main_branch:
-        success = install_from_main_branch(io)
-        analytics.event("exit", reason="Installed main branch")
+    # Handle --install-branch [url]
+    if args.install_branch:
+        if isinstance(args.install_branch, str):
+            success = install_from_git_branch(io, remote_url=args.install_branch)
+        else:  # True, meaning the flag was used without a URL
+            success = install_from_git_branch(io)
+        analytics.event("exit", reason="Installed git branch")
         return 0 if success else 1
 
     if args.upgrade:
diff --git a/aider/versioncheck.py b/aider/versioncheck.py
index ac511a022..b350614f9 100644
--- a/aider/versioncheck.py
+++ b/aider/versioncheck.py
@@ -12,16 +12,23 @@ from aider.dump import dump  # noqa: F401
 VERSION_CHECK_FNAME = Path.home() / ".aider" / "caches" / "versioncheck"
 
 
-def install_from_main_branch(io):
+def install_from_git_branch(io, remote_url=None):
     """
-    Install the latest version of aider from the main branch of the GitHub repository.
+    Install the latest version of aider from the main branch of the GitHub repository
+    or a specified git remote URL.
     """
 
+    if remote_url is None:
+        remote_url = "git+https://github.com/Aider-AI/aider.git@main"
+        source_description = "the Aider-AI main branch"
+    else:
+        source_description = remote_url
+
     return utils.check_pip_install_extra(
         io,
         None,
-        "Install the development version of aider from the main branch?",
-        ["git+https://github.com/Aider-AI/aider.git"],
+        f"Install the development version of aider from {source_description}?",
+        [remote_url],
         self_update=True,
     )
 
diff --git a/aider/website/docs/config/aider_conf.md b/aider/website/docs/config/aider_conf.md
index 99bccf401..da45f0b11 100644
--- a/aider/website/docs/config/aider_conf.md
+++ b/aider/website/docs/config/aider_conf.md
@@ -361,8 +361,8 @@ cog.outl("```")
 ## Show release notes on first run of new version (default: None, ask user)
 #show-release-notes: xxx
 
-## Install the latest version from the main branch
-#install-main-branch: false
+## Install the latest version from a git branch. If GIT_URL is provided, installs from that URL (e.g., git+https://github.com/user/aider.git@my-branch). If no URL is provided, installs from the Aider-AI main branch.
+#install-branch: false
 
 ## Upgrade aider to the latest version from PyPI
 #upgrade: false
diff --git a/aider/website/docs/config/options.md b/aider/website/docs/config/options.md
index 368c4ec7e..7dfbda548 100644
--- a/aider/website/docs/config/options.md
+++ b/aider/website/docs/config/options.md
@@ -66,8 +66,7 @@ usage: aider [-h] [--model] [--openai-api-key] [--anthropic-api-key]
              [--analytics | --no-analytics] [--analytics-log]
              [--analytics-disable] [--just-check-update]
              [--check-update | --no-check-update]
-             [--show-release-notes | --no-show-release-notes]
-             [--install-main-branch] [--upgrade] [--version]
+             [--show-release-notes | --no-show-release-notes] [--install-branch] [--upgrade] [--version]
              [--message] [--message-file]
              [--gui | --no-gui | --browser | --no-browser]
              [--copy-paste | --no-copy-paste] [--apply]
@@ -568,10 +567,10 @@ Aliases:
   - `--show-release-notes`
   - `--no-show-release-notes`
 
-### `--install-main-branch`
-Install the latest version from the main branch  
+### `--install-branch [GIT_URL]`
+Install the latest version from a git branch. If GIT_URL is provided, installs from that URL (e.g., git+https://github.com/user/aider.git@my-branch). If no URL is provided, installs from the Aider-AI main branch.  
 Default: False  
-Environment variable: `AIDER_INSTALL_MAIN_BRANCH`  
+Environment variable: `AIDER_INSTALL_BRANCH`  
 
 ### `--upgrade`
 Upgrade aider to the latest version from PyPI