diff --git a/src/libfetchers/github.cc b/src/libfetchers/github.cc
index c01917dcc..e59c83be4 100644
--- a/src/libfetchers/github.cc
+++ b/src/libfetchers/github.cc
@@ -8,21 +8,18 @@
 
 namespace nix::fetchers {
 
-std::regex ownerRegex("[a-zA-Z][a-zA-Z0-9_-]*", std::regex::ECMAScript);
-std::regex repoRegex("[a-zA-Z][a-zA-Z0-9_-]*", std::regex::ECMAScript);
-
-struct GitHubInput : Input
+struct GitArchiveInput : Input
 {
     std::string owner;
     std::string repo;
     std::optional<std::string> ref;
     std::optional<Hash> rev;
 
-    std::string type() const override { return "github"; }
+    virtual std::shared_ptr<GitArchiveInput> _clone() const = 0;
 
     bool operator ==(const Input & other) const override
     {
-        auto other2 = dynamic_cast<const GitHubInput *>(&other);
+        auto other2 = dynamic_cast<const GitArchiveInput *>(&other);
         return
             other2
             && owner == other2->owner
@@ -47,7 +44,7 @@ struct GitHubInput : Input
         if (ref) path += "/" + *ref;
         if (rev) path += "/" + rev->to_string(Base16, false);
         return ParsedURL {
-            .scheme = "github",
+            .scheme = type(),
             .path = path,
         };
     }
@@ -64,30 +61,18 @@ struct GitHubInput : Input
         return attrs;
     }
 
-    void clone(const Path & destDir) const override
-    {
-        std::shared_ptr<const Input> input = inputFromURL(fmt("git+ssh://git@github.com/%s/%s.git", owner, repo));
-        input = input->applyOverrides(ref.value_or("master"), rev);
-        input->clone(destDir);
-    }
+    virtual Hash getRevFromRef(nix::ref<Store> store, std::string_view ref) const = 0;
+
+    virtual std::string getDownloadUrl() const = 0;
 
     std::pair<Tree, std::shared_ptr<const Input>> fetchTreeInternal(nix::ref<Store> store) const override
     {
         auto rev = this->rev;
         auto ref = this->ref.value_or("master");
 
-        if (!rev) {
-            auto url = fmt("https://api.github.com/repos/%s/%s/commits/%s",
-                owner, repo, ref);
-            auto json = nlohmann::json::parse(
-                readFile(
-                    store->toRealPath(
-                        downloadFile(store, url, "source", false).storePath)));
-            rev = Hash(json["sha"], htSHA1);
-            debug("HEAD revision for '%s' is %s", url, rev->gitRev());
-        }
+        if (!rev) rev = getRevFromRef(store, ref);
 
-        auto input = std::make_shared<GitHubInput>(*this);
+        auto input = _clone();
         input->ref = {};
         input->rev = *rev;
 
@@ -109,15 +94,8 @@ struct GitHubInput : Input
             };
         }
 
-        // FIXME: use regular /archive URLs instead? api.github.com
-        // might have stricter rate limits.
+        auto url = input->getDownloadUrl();
 
-        auto url = fmt("https://api.github.com/repos/%s/%s/tarball/%s",
-            owner, repo, rev->to_string(Base16, false));
-
-        std::string accessToken = settings.githubAccessToken.get();
-        if (accessToken != "")
-            url += "?access_token=" + accessToken;
 
         auto tree = downloadTarball(store, url, "source", true);
 
@@ -140,7 +118,7 @@ struct GitHubInput : Input
     {
         if (!ref && !rev) return shared_from_this();
 
-        auto res = std::make_shared<GitHubInput>(*this);
+        auto res = _clone();
 
         if (ref) res->ref = ref;
         if (rev) res->rev = rev;
@@ -149,14 +127,21 @@ struct GitHubInput : Input
     }
 };
 
-struct GitHubInputScheme : InputScheme
+struct GitArchiveInputScheme : InputScheme
 {
+    std::string type;
+
+    GitArchiveInputScheme(std::string && type) : type(type)
+    { }
+
+    virtual std::unique_ptr<GitArchiveInput> create() = 0;
+
     std::unique_ptr<Input> inputFromURL(const ParsedURL & url) override
     {
-        if (url.scheme != "github") return nullptr;
+        if (url.scheme != type) return nullptr;
 
         auto path = tokenizeString<std::vector<std::string>>(url.path, "/");
-        auto input = std::make_unique<GitHubInput>();
+        auto input = create();
 
         if (path.size() == 2) {
         } else if (path.size() == 3) {
@@ -165,27 +150,27 @@ struct GitHubInputScheme : InputScheme
             else if (std::regex_match(path[2], refRegex))
                 input->ref = path[2];
             else
-                throw BadURL("in GitHub URL '%s', '%s' is not a commit hash or branch/tag name", url.url, path[2]);
+                throw BadURL("in URL '%s', '%s' is not a commit hash or branch/tag name", url.url, path[2]);
         } else
-            throw BadURL("GitHub URL '%s' is invalid", url.url);
+            throw BadURL("URL '%s' is invalid", url.url);
 
         for (auto &[name, value] : url.query) {
             if (name == "rev") {
                 if (input->rev)
-                    throw BadURL("GitHub URL '%s' contains multiple commit hashes", url.url);
+                    throw BadURL("URL '%s' contains multiple commit hashes", url.url);
                 input->rev = Hash(value, htSHA1);
             }
             else if (name == "ref") {
                 if (!std::regex_match(value, refRegex))
-                    throw BadURL("GitHub URL '%s' contains an invalid branch/tag name", url.url);
+                    throw BadURL("URL '%s' contains an invalid branch/tag name", url.url);
                 if (input->ref)
-                    throw BadURL("GitHub URL '%s' contains multiple branch/tag names", url.url);
+                    throw BadURL("URL '%s' contains multiple branch/tag names", url.url);
                 input->ref = value;
             }
         }
 
         if (input->ref && input->rev)
-            throw BadURL("GitHub URL '%s' contains both a commit hash and a branch/tag name", url.url);
+            throw BadURL("URL '%s' contains both a commit hash and a branch/tag name", url.url);
 
         input->owner = path[0];
         input->repo = path[1];
@@ -195,13 +180,13 @@ struct GitHubInputScheme : InputScheme
 
     std::unique_ptr<Input> inputFromAttrs(const Attrs & attrs) override
     {
-        if (maybeGetStrAttr(attrs, "type") != "github") return {};
+        if (maybeGetStrAttr(attrs, "type") != type) return {};
 
         for (auto & [name, value] : attrs)
             if (name != "type" && name != "owner" && name != "repo" && name != "ref" && name != "rev")
-                throw Error("unsupported GitHub input attribute '%s'", name);
+                throw Error("unsupported input attribute '%s'", name);
 
-        auto input = std::make_unique<GitHubInput>();
+        auto input = create();
         input->owner = getStrAttr(attrs, "owner");
         input->repo = getStrAttr(attrs, "repo");
         input->ref = maybeGetStrAttr(attrs, "ref");
@@ -211,6 +196,113 @@ struct GitHubInputScheme : InputScheme
     }
 };
 
+struct GitHubInput : GitArchiveInput
+{
+    std::string type() const override { return "github"; }
+
+    std::shared_ptr<GitArchiveInput> _clone() const override
+    { return std::make_shared<GitHubInput>(*this); }
+
+    Hash getRevFromRef(nix::ref<Store> store, std::string_view ref) const override
+    {
+        auto url = fmt("https://api.github.com/repos/%s/%s/commits/%s",
+            owner, repo, ref);
+        auto json = nlohmann::json::parse(
+            readFile(
+                store->toRealPath(
+                    downloadFile(store, url, "source", false).storePath)));
+        auto rev = Hash(json["sha"], htSHA1);
+        debug("HEAD revision for '%s' is %s", url, rev.gitRev());
+        return rev;
+    }
+
+    std::string getDownloadUrl() const override
+    {
+        // FIXME: use regular /archive URLs instead? api.github.com
+        // might have stricter rate limits.
+
+        auto url = fmt("https://api.github.com/repos/%s/%s/tarball/%s",
+            owner, repo, rev->to_string(Base16, false));
+
+        std::string accessToken = settings.githubAccessToken.get();
+        if (accessToken != "")
+            url += "?access_token=" + accessToken;
+
+        return url;
+    }
+
+    void clone(const Path & destDir) const override
+    {
+        std::shared_ptr<const Input> input = inputFromURL(fmt("git+ssh://git@github.com/%s/%s.git", owner, repo));
+        input = input->applyOverrides(ref.value_or("master"), rev);
+        input->clone(destDir);
+    }
+};
+
+struct GitHubInputScheme : GitArchiveInputScheme
+{
+    GitHubInputScheme() : GitArchiveInputScheme("github") { }
+
+    std::unique_ptr<GitArchiveInput> create() override
+    {
+        return std::make_unique<GitHubInput>();
+    }
+};
+
+struct GitLabInput : GitArchiveInput
+{
+    std::string type() const override { return "gitlab"; }
+
+    std::shared_ptr<GitArchiveInput> _clone() const override
+    { return std::make_shared<GitLabInput>(*this); }
+
+    Hash getRevFromRef(nix::ref<Store> store, std::string_view ref) const override
+    {
+        auto url = fmt("https://gitlab.com/api/v4/projects/%s%%2F%s/repository/branches/%s",
+            owner, repo, ref);
+        auto json = nlohmann::json::parse(
+            readFile(
+                store->toRealPath(
+                    downloadFile(store, url, "source", false).storePath)));
+        auto rev = Hash(json["commit"]["id"], htSHA1);
+        debug("HEAD revision for '%s' is %s", url, rev.gitRev());
+        return rev;
+    }
+
+    std::string getDownloadUrl() const override
+    {
+        // FIXME: This endpoint has a rate limit threshold of 5 requests per minute.
+
+        auto url = fmt("https://gitlab.com/api/v4/projects/%s%%2F%s/repository/archive.tar.gz?sha=%s",
+            owner, repo, rev->to_string(Base16, false));
+
+        /* # FIXME: add privat token auth (`curl --header "PRIVATE-TOKEN: <your_access_token>"`)
+        std::string accessToken = settings.githubAccessToken.get();
+        if (accessToken != "")
+            url += "?access_token=" + accessToken;*/
+
+        return url;
+    }
+
+    void clone(const Path & destDir) const override
+    {
+        std::shared_ptr<const Input> input = inputFromURL(fmt("git+ssh://git@gitlab.com/%s/%s.git", owner, repo));
+        input = input->applyOverrides(ref.value_or("master"), rev);
+        input->clone(destDir);
+    }
+};
+
+struct GitLabInputScheme : GitArchiveInputScheme
+{
+    GitLabInputScheme() : GitArchiveInputScheme("gitlab") { }
+
+    std::unique_ptr<GitArchiveInput> create() override
+    {
+        return std::make_unique<GitLabInput>();
+    }
+};
+
 static auto r1 = OnStartup([] { registerInputScheme(std::make_unique<GitHubInputScheme>()); });
+static auto r2 = OnStartup([] { registerInputScheme(std::make_unique<GitLabInputScheme>()); });
 
 }
diff --git a/src/libfetchers/gitlab.cc b/src/libfetchers/gitlab.cc
deleted file mode 100644
index 9f47e69fe..000000000
--- a/src/libfetchers/gitlab.cc
+++ /dev/null
@@ -1,213 +0,0 @@
-#include "filetransfer.hh"
-#include "cache.hh"
-#include "fetchers.hh"
-#include "globals.hh"
-#include "store-api.hh"
-
-#include <nlohmann/json.hpp>
-
-namespace nix::fetchers {
-
-struct GitLabInput : Input
-{
-    std::string owner;
-    std::string repo;
-    std::optional<std::string> ref;
-    std::optional<Hash> rev;
-
-    std::string type() const override { return "gitlab"; }
-
-    bool operator ==(const Input & other) const override
-    {
-        auto other2 = dynamic_cast<const GitLabInput *>(&other);
-        return
-            other2
-            && owner == other2->owner
-            && repo == other2->repo
-            && rev == other2->rev
-            && ref == other2->ref;
-    }
-
-    bool isImmutable() const override
-    {
-        return (bool) rev || narHash;
-    }
-
-    std::optional<std::string> getRef() const override { return ref; }
-
-    std::optional<Hash> getRev() const override { return rev; }
-
-    ParsedURL toURL() const override
-    {
-        auto path = owner + "/" + repo;
-        assert(!(ref && rev));
-        if (ref) path += "/" + *ref;
-        if (rev) path += "/" + rev->to_string(Base16, false);
-        return ParsedURL {
-            .scheme = "gitlab",
-            .path = path,
-        };
-    }
-
-    Attrs toAttrsInternal() const override
-    {
-        Attrs attrs;
-        attrs.emplace("owner", owner);
-        attrs.emplace("repo", repo);
-        if (ref)
-            attrs.emplace("ref", *ref);
-        if (rev)
-            attrs.emplace("rev", rev->gitRev());
-        return attrs;
-    }
-
-    void clone(const Path & destDir) const override
-    {
-        std::shared_ptr<const Input> input = inputFromURL(fmt("git+ssh://git@gitlab.com/%s/%s.git", owner, repo));
-        input = input->applyOverrides(ref.value_or("master"), rev);
-        input->clone(destDir);
-    }
-
-    std::pair<Tree, std::shared_ptr<const Input>> fetchTreeInternal(nix::ref<Store> store) const override
-    {
-        auto rev = this->rev;
-        auto ref = this->ref.value_or("master");
-
-        if (!rev) {
-            auto url = fmt("https://gitlab.com/api/v4/projects/%s%%2F%s/repository/branches/%s",
-                owner, repo, ref);
-            auto json = nlohmann::json::parse(
-                readFile(
-                    store->toRealPath(
-                        downloadFile(store, url, "source", false).storePath)));
-            rev = Hash(json["commit"]["id"], htSHA1);
-            debug("HEAD revision for '%s' is %s", url, rev->gitRev());
-        }
-
-        auto input = std::make_shared<GitLabInput>(*this);
-        input->ref = {};
-        input->rev = *rev;
-
-        Attrs immutableAttrs({
-            {"type", "git-tarball"},
-            {"rev", rev->gitRev()},
-        });
-
-        if (auto res = getCache()->lookup(store, immutableAttrs)) {
-            return {
-                Tree{
-                    .actualPath = store->toRealPath(res->second),
-                    .storePath = std::move(res->second),
-                    .info = TreeInfo {
-                        .lastModified = getIntAttr(res->first, "lastModified"),
-                    },
-                },
-                input
-            };
-        }
-
-        // FIXME: This endpoint has a rate limit threshold of 5 requests per minute.
-
-        auto url = fmt("https://gitlab.com/api/v4/projects/%s%%2F%s/repository/archive.tar.gz?sha=%s",
-            owner, repo, rev->to_string(Base16, false));
-
-        /* # FIXME: add privat token auth (`curl --header "PRIVATE-TOKEN: <your_access_token>"`)
-        std::string accessToken = settings.githubAccessToken.get();
-        if (accessToken != "")
-            url += "?access_token=" + accessToken;*/
-
-        auto tree = downloadTarball(store, url, "source", true);
-
-        getCache()->add(
-            store,
-            immutableAttrs,
-            {
-                {"rev", rev->gitRev()},
-                {"lastModified", *tree.info.lastModified}
-            },
-            tree.storePath,
-            true);
-
-        return {std::move(tree), input};
-    }
-
-    std::shared_ptr<const Input> applyOverrides(
-        std::optional<std::string> ref,
-        std::optional<Hash> rev) const override
-    {
-        if (!ref && !rev) return shared_from_this();
-
-        auto res = std::make_shared<GitLabInput>(*this);
-
-        if (ref) res->ref = ref;
-        if (rev) res->rev = rev;
-
-        return res;
-    }
-};
-
-struct GitLabInputScheme : InputScheme
-{
-    std::unique_ptr<Input> inputFromURL(const ParsedURL & url) override
-    {
-        if (url.scheme != "gitlab") return nullptr;
-
-        auto path = tokenizeString<std::vector<std::string>>(url.path, "/");
-        auto input = std::make_unique<GitLabInput>();
-
-        if (path.size() == 2) {
-        } else if (path.size() == 3) {
-            if (std::regex_match(path[2], revRegex))
-                input->rev = Hash(path[2], htSHA1);
-            else if (std::regex_match(path[2], refRegex))
-                input->ref = path[2];
-            else
-                throw BadURL("in GitLab URL '%s', '%s' is not a commit hash or branch/tag name", url.url, path[2]);
-        } else
-            throw BadURL("GitLab URL '%s' is invalid", url.url);
-
-        for (auto &[name, value] : url.query) {
-            if (name == "rev") {
-                if (input->rev)
-                    throw BadURL("GitLab URL '%s' contains multiple commit hashes", url.url);
-                input->rev = Hash(value, htSHA1);
-            }
-            else if (name == "ref") {
-                if (!std::regex_match(value, refRegex))
-                    throw BadURL("GitLab URL '%s' contains an invalid branch/tag name", url.url);
-                if (input->ref)
-                    throw BadURL("GitLab URL '%s' contains multiple branch/tag names", url.url);
-                input->ref = value;
-            }
-        }
-
-        if (input->ref && input->rev)
-            throw BadURL("GitLab URL '%s' contains both a commit hash and a branch/tag name", url.url);
-
-        input->owner = path[0];
-        input->repo = path[1];
-
-        return input;
-    }
-
-    std::unique_ptr<Input> inputFromAttrs(const Attrs & attrs) override
-    {
-        if (maybeGetStrAttr(attrs, "type") != "gitlab") return {};
-
-        for (auto & [name, value] : attrs)
-            if (name != "type" && name != "owner" && name != "repo" && name != "ref" && name != "rev")
-                throw Error("unsupported GitLab input attribute '%s'", name);
-
-        auto input = std::make_unique<GitLabInput>();
-        input->owner = getStrAttr(attrs, "owner");
-        input->repo = getStrAttr(attrs, "repo");
-        input->ref = maybeGetStrAttr(attrs, "ref");
-        if (auto rev = maybeGetStrAttr(attrs, "rev"))
-            input->rev = Hash(*rev, htSHA1);
-        return input;
-    }
-};
-
-static auto r1 = OnStartup([] { registerInputScheme(std::make_unique<GitLabInputScheme>()); });
-
-}