diff --git a/app/views/shared/_import_form.html.haml b/app/views/shared/_import_form.html.haml
index 233d8c95eda..736afa085e8 100644
--- a/app/views/shared/_import_form.html.haml
+++ b/app/views/shared/_import_form.html.haml
@@ -11,6 +11,7 @@
       %li
         If your HTTP repository is not publicly accessible, add authentication information to the URL: <code>https://username:password@gitlab.company.com/group/project.git</code>.
       %li
-        The import will time out after 15 minutes. For repositories that take longer, use a clone/push combination.
+        The import will time out after #{time_interval_in_words(Gitlab.config.gitlab_shell.git_timeout)}.
+        For repositories that take longer, use a clone/push combination.
       %li
         To migrate an SVN repository, check out #{link_to "this document", help_page_path('user/project/import/svn')}.
diff --git a/changelogs/unreleased/39977-gitlab-shell-default-timeout.yml b/changelogs/unreleased/39977-gitlab-shell-default-timeout.yml
new file mode 100644
index 00000000000..b7a974fd8d9
--- /dev/null
+++ b/changelogs/unreleased/39977-gitlab-shell-default-timeout.yml
@@ -0,0 +1,5 @@
+---
+title: Set the default gitlab-shell timeout to 3 hours
+merge_request: 15292
+author:
+type: fixed
diff --git a/config/gitlab.yml.example b/config/gitlab.yml.example
index 7547ba4a8fa..7f6e68ceed6 100644
--- a/config/gitlab.yml.example
+++ b/config/gitlab.yml.example
@@ -559,8 +559,8 @@ production: &base
     upload_pack: true
     receive_pack: true
 
-    # Git import/fetch timeout
-    # git_timeout: 800
+    # Git import/fetch timeout, in seconds. Defaults to 3 hours.
+    # git_timeout: 10800
 
     # If you use non-standard ssh port you need to specify it
     # ssh_port: 22
diff --git a/config/initializers/1_settings.rb b/config/initializers/1_settings.rb
index d1156b0c8a8..f7c83f7b0f7 100644
--- a/config/initializers/1_settings.rb
+++ b/config/initializers/1_settings.rb
@@ -429,7 +429,7 @@ Settings.gitlab_shell['ssh_port']     ||= 22
 Settings.gitlab_shell['ssh_user']     ||= Settings.gitlab.user
 Settings.gitlab_shell['owner_group']  ||= Settings.gitlab.user
 Settings.gitlab_shell['ssh_path_prefix'] ||= Settings.__send__(:build_gitlab_shell_ssh_path_prefix)
-Settings.gitlab_shell['git_timeout'] ||= 800
+Settings.gitlab_shell['git_timeout'] ||= 10800
 
 #
 # Workhorse
diff --git a/lib/gitlab/shell.rb b/lib/gitlab/shell.rb
index dc0184e4ad9..996d213fdb4 100644
--- a/lib/gitlab/shell.rb
+++ b/lib/gitlab/shell.rb
@@ -101,8 +101,7 @@ module Gitlab
     #
     # Gitaly migration: https://gitlab.com/gitlab-org/gitaly/issues/387
     def import_repository(storage, name, url)
-      # Timeout should be less than 900 ideally, to prevent the memory killer
-      # to silently kill the process without knowing we are timing out here.
+      # The timeout ensures the subprocess won't hang forever
       cmd = [gitlab_shell_projects_path, 'import-project',
              storage, "#{name}.git", url, "#{Gitlab.config.gitlab_shell.git_timeout}"]
       gitlab_shell_fast_execute_raise_error(cmd)