diff --git a/cpp/CMakeLists.txt b/cpp/CMakeLists.txt
index 4bdd210..3cb8e88 100644
--- a/cpp/CMakeLists.txt
+++ b/cpp/CMakeLists.txt
@@ -20,13 +20,16 @@ add_library(lubuntuci SHARED common.cpp utilities.cpp)
 target_include_directories(lubuntuci PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_link_libraries(lubuntuci PUBLIC yaml-cpp::yaml-cpp PRIVATE CURL::libcurl /srv/lubuntu-ci/repos/ci-tools/lib/liblaunchpad.so)
 
+add_library(update_maintainer_lib STATIC update-maintainer-lib.cpp)
+target_include_directories(update_maintainer_lib PRIVATE /srv/lubuntu-ci/repos/ci-tools/include/launchpadlib-cpp)
+target_link_libraries(update_maintainer_lib PRIVATE lubuntuci yaml-cpp::yaml-cpp CURL::libcurl)
+
 add_executable(update-maintainer update-maintainer.cpp)
-target_include_directories(update-maintainer PRIVATE /srv/lubuntu-ci/repos/ci-tools/include/launchpadlib-cpp)
-target_link_libraries(update-maintainer PRIVATE lubuntuci yaml-cpp::yaml-cpp CURL::libcurl)
+target_link_libraries(update-maintainer PRIVATE update_maintainer_lib)
 
 add_executable(build-packages build-packages.cpp)
 target_include_directories(build-packages PRIVATE /srv/lubuntu-ci/repos/ci-tools/include/launchpadlib-cpp)
-target_link_libraries(build-packages PRIVATE lubuntuci PkgConfig::LIBGIT2 yaml-cpp::yaml-cpp)
+target_link_libraries(build-packages PRIVATE lubuntuci PkgConfig::LIBGIT2 update_maintainer_lib yaml-cpp::yaml-cpp)
 
 add_executable(fetch-indexes fetch-indexes.cpp utilities.cpp)
 target_include_directories(fetch-indexes PRIVATE /srv/lubuntu-ci/repos/ci-tools/include/launchpadlib-cpp)
diff --git a/cpp/build-packages.cpp b/cpp/build-packages.cpp
index d3d0de6..75e9dcb 100644
--- a/cpp/build-packages.cpp
+++ b/cpp/build-packages.cpp
@@ -14,7 +14,7 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 #include "common.h"
-#include "update-maintainer.h"
+#include "update-maintainer-lib.h"
 #include <iostream>
 #include <fstream>
 #include <sstream>
diff --git a/cpp/update-maintainer-lib.cpp b/cpp/update-maintainer-lib.cpp
new file mode 100644
index 0000000..a8e7fe2
--- /dev/null
+++ b/cpp/update-maintainer-lib.cpp
@@ -0,0 +1,215 @@
+// Copyright (C) 2024 Simon Quigley <tsimonq2@ubuntu.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#include "update-maintainer-lib.h"
+#include "update-maintainer.h"
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+#include <regex>
+#include <stdexcept>
+#include <string>
+#include <optional>
+
+namespace fs = std::filesystem;
+
+// Definitions from update-maintainer.cpp moved here
+static const char* PREVIOUS_UBUNTU_MAINTAINERS[] = {
+    "ubuntu core developers <ubuntu-devel@lists.ubuntu.com>",
+    "ubuntu core developers <ubuntu-devel-discuss@lists.ubuntu.com>",
+    "ubuntu motu developers <ubuntu-motu@lists.ubuntu.com>"
+};
+static const char* UBUNTU_MAINTAINER = "Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>";
+
+class MaintainerUpdateException : public std::runtime_error {
+public:
+    using std::runtime_error::runtime_error;
+};
+
+static std::optional<fs::path> find_control_file(const fs::path &debian_dir) {
+    fs::path control_in = debian_dir / "control.in";
+    fs::path control = debian_dir / "control";
+    if (fs::exists(control_in)) return control_in;
+    if (fs::exists(control)) return control;
+    return std::nullopt;
+}
+
+static fs::path find_changelog_file(const fs::path &debian_dir) {
+    fs::path changelog = debian_dir / "changelog";
+    if (!fs::exists(changelog)) {
+        throw MaintainerUpdateException("No changelog file found");
+    }
+    return changelog;
+}
+
+static bool xsbc_managed_by_rules(const fs::path &debian_dir) {
+    fs::path rules = debian_dir / "rules";
+    if (!fs::exists(rules)) return false;
+    std::ifstream rf(rules);
+    std::string line;
+    while (std::getline(rf, line)) {
+        if (line.find("XSBC-Original-") != std::string::npos) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static std::string get_distribution(const fs::path &changelog_file) {
+    // parse first line of changelog: "package (version) dist; urgency=..."
+    // dist is the token after ')'
+    std::ifstream f(changelog_file);
+    if(!f) throw MaintainerUpdateException("Unable to open changelog.");
+    std::string first_line;
+    std::getline(f, first_line);
+    size_t pos = first_line.find(')');
+    if(pos == std::string::npos) throw MaintainerUpdateException("Invalid changelog format");
+    pos++;
+    while(pos < first_line.size() && std::isspace((unsigned char)first_line[pos])) pos++;
+    size_t start = pos;
+    while(pos < first_line.size() && !std::isspace((unsigned char)first_line[pos]) && first_line[pos] != ';') pos++;
+    std::string dist = first_line.substr(start, pos - start);
+    size_t dashpos = dist.find('-');
+    if (dashpos != std::string::npos) {
+        dist = dist.substr(0, dashpos);
+    }
+    return dist;
+}
+
+static std::string read_file(const fs::path &p) {
+    std::ifstream f(p);
+    if(!f) throw MaintainerUpdateException("Cannot read file: " + p.string());
+    std::stringstream ss;
+    ss << f.rdbuf();
+    return ss.str();
+}
+
+static void write_file(const fs::path &p, const std::string &content) {
+    std::ofstream f(p);
+    if(!f) throw MaintainerUpdateException("Cannot write file: " + p.string());
+    f << content;
+}
+
+static std::optional<std::string> get_field(const std::string &content, const std::string &field_regex) {
+    std::regex r(field_regex, std::regex_constants::multiline);
+    std::smatch m;
+    if(std::regex_search(content, m, r)) {
+        return m[1].str();
+    }
+    return std::nullopt;
+}
+
+static std::string set_field(const std::string &content, const std::string &field_regex, const std::string &new_line) {
+    std::regex r(field_regex, std::regex_constants::multiline);
+    return std::regex_replace(content, r, new_line);
+}
+
+static void update_maintainer_file(const fs::path &control_file, const std::string &distribution, bool verbose) {
+    std::string c = read_file(control_file);
+
+    auto original_maintainer = get_field(c, "^Maintainer:\\s?(.*)$");
+    if(!original_maintainer) {
+        throw MaintainerUpdateException("No Maintainer field found");
+    }
+
+    std::string om = *original_maintainer;
+    std::string om_lower = om;
+    for (auto &ch : om_lower) ch = (char)std::tolower((unsigned char)ch);
+
+    // Check previous ubuntu maintainers
+    for (auto &pm : PREVIOUS_UBUNTU_MAINTAINERS) {
+        std::string pm_lower = pm;
+        for (auto &ch: pm_lower) ch=(char)std::tolower((unsigned char)ch);
+        if(pm_lower == om_lower) {
+            if(verbose) {
+                std::cout<<"The old maintainer was: "<<om<<"\n";
+                std::cout<<"Resetting as: "<<UBUNTU_MAINTAINER<<"\n";
+            }
+            // just set maintainer
+            std::regex maint_re("^Maintainer:\\s?.*$", std::regex_constants::multiline);
+            c = std::regex_replace(c, maint_re, "Maintainer: " + std::string(UBUNTU_MAINTAINER));
+            write_file(control_file, c);
+            return;
+        }
+    }
+
+    // If ends with ubuntu.com, do nothing
+    {
+        std::string lower_om = om_lower;
+        if (lower_om.rfind("ubuntu.com>", lower_om.size()-11) != std::string::npos) {
+            if(verbose) {
+                std::cout<<"The Maintainer email is ubuntu.com address. Doing nothing.\n";
+            }
+            return;
+        }
+    }
+
+    // Debian distributions: stable, testing, unstable, experimental
+    if(distribution=="stable"||distribution=="testing"||distribution=="unstable"||distribution=="experimental") {
+        if(verbose) {
+            std::cout<<"The package targets Debian. Doing nothing.\n";
+        }
+        return;
+    }
+
+    // set XSBC-Original-Maintainer if needed
+    auto orig_field = get_field(c, "^(?:[XSBC]*-)?Original-Maintainer:\\s?(.*)$");
+    if(orig_field && verbose) {
+        std::cout<<"Overwriting original maintainer: "<< *orig_field <<"\n";
+    }
+
+    if(verbose) {
+        std::cout<<"The original maintainer is: "<< om <<"\n";
+        std::cout<<"Resetting as: "<<UBUNTU_MAINTAINER<<"\n";
+    }
+
+    // set original maint
+    if(orig_field) {
+        // pattern to replace original maint
+        std::regex orig_re("^(?:[XSBC]*-)?Original-Maintainer:.*$", std::regex_constants::multiline);
+        c = std::regex_replace(c, orig_re, "XSBC-Original-Maintainer: " + om);
+    } else {
+        // insert after Maintainer line
+        std::regex maint_re("^(Maintainer:.*)$", std::regex_constants::multiline);
+        c = std::regex_replace(c, maint_re, "$1\nXSBC-Original-Maintainer: " + om);
+    }
+
+    // now set maint
+    {
+        std::regex maint_re("^Maintainer:\\s?.*$", std::regex_constants::multiline);
+        c = std::regex_replace(c, maint_re, "Maintainer: " + std::string(UBUNTU_MAINTAINER));
+    }
+
+    write_file(control_file, c);
+}
+
+void update_maintainer(const std::string &debian_directory, bool verbose) {
+    fs::path debian_dir(debian_directory);
+    auto control_file = find_control_file(debian_dir);
+    if(!control_file) {
+        throw MaintainerUpdateException("No control file found");
+    }
+    fs::path changelog = find_changelog_file(debian_dir);
+    if(xsbc_managed_by_rules(debian_dir)) {
+        if(verbose) {
+            std::cout<<"XSBC-Original is managed by rules. Doing nothing.\n";
+        }
+        return;
+    }
+
+    std::string distribution = get_distribution(changelog);
+
+    update_maintainer_file(*control_file, distribution, verbose);
+}
diff --git a/cpp/update-maintainer-lib.h b/cpp/update-maintainer-lib.h
new file mode 100644
index 0000000..d5c315b
--- /dev/null
+++ b/cpp/update-maintainer-lib.h
@@ -0,0 +1,19 @@
+// Copyright (C) 2024 Simon Quigley <tsimonq2@ubuntu.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#pragma once
+#include <string>
+
+void update_maintainer(const std::string &debian_directory, bool verbose = false);
diff --git a/cpp/update-maintainer.cpp b/cpp/update-maintainer.cpp
index db8191e..b7aa275 100644
--- a/cpp/update-maintainer.cpp
+++ b/cpp/update-maintainer.cpp
@@ -13,206 +13,10 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-#include "update-maintainer.h"
-#include <filesystem>
-#include <fstream>
+#include "update-maintainer-lib.h"
 #include <iostream>
-#include <regex>
-#include <stdexcept>
-#include <string>
-#include <optional>
 
-namespace fs = std::filesystem;
-
-static const char* PREVIOUS_UBUNTU_MAINTAINERS[] = {
-    "ubuntu core developers <ubuntu-devel@lists.ubuntu.com>",
-    "ubuntu core developers <ubuntu-devel-discuss@lists.ubuntu.com>",
-    "ubuntu motu developers <ubuntu-motu@lists.ubuntu.com>"
-};
-static const char* UBUNTU_MAINTAINER = "Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>";
-
-class MaintainerUpdateException : public std::runtime_error {
-public:
-    using std::runtime_error::runtime_error;
-};
-
-static std::optional<fs::path> find_control_file(const fs::path &debian_dir) {
-    fs::path control_in = debian_dir / "control.in";
-    fs::path control = debian_dir / "control";
-    if (fs::exists(control_in)) return control_in;
-    if (fs::exists(control)) return control;
-    return std::nullopt;
-}
-
-static fs::path find_changelog_file(const fs::path &debian_dir) {
-    fs::path changelog = debian_dir / "changelog";
-    if (!fs::exists(changelog)) {
-        throw MaintainerUpdateException("No changelog file found");
-    }
-    return changelog;
-}
-
-static bool xsbc_managed_by_rules(const fs::path &debian_dir) {
-    fs::path rules = debian_dir / "rules";
-    if (!fs::exists(rules)) return false;
-    std::ifstream rf(rules);
-    std::string line;
-    while (std::getline(rf, line)) {
-        if (line.find("XSBC-Original-") != std::string::npos) {
-            return true;
-        }
-    }
-    return false;
-}
-
-static std::string get_distribution(const fs::path &changelog_file) {
-    // parse first line of changelog: "package (version) dist; urgency=..."
-    // dist is the token after ')'
-    std::ifstream f(changelog_file);
-    if(!f) throw MaintainerUpdateException("Unable to open changelog.");
-    std::string first_line;
-    std::getline(f, first_line);
-    size_t pos = first_line.find(')');
-    if(pos == std::string::npos) throw MaintainerUpdateException("Invalid changelog format");
-    pos++;
-    while(pos < first_line.size() && std::isspace((unsigned char)first_line[pos])) pos++;
-    size_t start = pos;
-    while(pos < first_line.size() && !std::isspace((unsigned char)first_line[pos]) && first_line[pos] != ';') pos++;
-    std::string dist = first_line.substr(start, pos - start);
-    size_t dashpos = dist.find('-');
-    if (dashpos != std::string::npos) {
-        dist = dist.substr(0, dashpos);
-    }
-    return dist;
-}
-
-static std::string read_file(const fs::path &p) {
-    std::ifstream f(p);
-    if(!f) throw MaintainerUpdateException("Cannot read file: " + p.string());
-    std::stringstream ss;
-    ss << f.rdbuf();
-    return ss.str();
-}
-
-static void write_file(const fs::path &p, const std::string &content) {
-    std::ofstream f(p);
-    if(!f) throw MaintainerUpdateException("Cannot write file: " + p.string());
-    f << content;
-}
-
-static std::optional<std::string> get_field(const std::string &content, const std::string &field_regex) {
-    std::regex r(field_regex, std::regex_constants::multiline);
-    std::smatch m;
-    if(std::regex_search(content, m, r)) {
-        return m[1].str();
-    }
-    return std::nullopt;
-}
-
-static std::string set_field(const std::string &content, const std::string &field_regex, const std::string &new_line) {
-    std::regex r(field_regex, std::regex_constants::multiline);
-    return std::regex_replace(content, r, new_line);
-}
-
-static void update_maintainer_file(const fs::path &control_file, const std::string &distribution, bool verbose) {
-    std::string c = read_file(control_file);
-
-    auto original_maintainer = get_field(c, "^Maintainer:\\s?(.*)$");
-    if(!original_maintainer) {
-        throw MaintainerUpdateException("No Maintainer field found");
-    }
-
-    std::string om = *original_maintainer;
-    std::string om_lower = om;
-    for (auto &ch : om_lower) ch = (char)std::tolower((unsigned char)ch);
-
-    // Check previous ubuntu maintainers
-    for (auto &pm : PREVIOUS_UBUNTU_MAINTAINERS) {
-        std::string pm_lower = pm;
-        for (auto &ch: pm_lower) ch=(char)std::tolower((unsigned char)ch);
-        if(pm_lower == om_lower) {
-            if(verbose) {
-                std::cout<<"The old maintainer was: "<<om<<"\n";
-                std::cout<<"Resetting as: "<<UBUNTU_MAINTAINER<<"\n";
-            }
-            // just set maintainer
-            std::regex maint_re("^Maintainer:\\s?.*$", std::regex_constants::multiline);
-            c = std::regex_replace(c, maint_re, "Maintainer: " + std::string(UBUNTU_MAINTAINER));
-            write_file(control_file, c);
-            return;
-        }
-    }
-
-    // If ends with ubuntu.com, do nothing
-    {
-        std::string lower_om = om_lower;
-        if (lower_om.rfind("ubuntu.com>", lower_om.size()-11) != std::string::npos) {
-            if(verbose) {
-                std::cout<<"The Maintainer email is ubuntu.com address. Doing nothing.\n";
-            }
-            return;
-        }
-    }
-
-    // Debian distributions: stable, testing, unstable, experimental
-    if(distribution=="stable"||distribution=="testing"||distribution=="unstable"||distribution=="experimental") {
-        if(verbose) {
-            std::cout<<"The package targets Debian. Doing nothing.\n";
-        }
-        return;
-    }
-
-    // set XSBC-Original-Maintainer if needed
-    auto orig_field = get_field(c, "^(?:[XSBC]*-)?Original-Maintainer:\\s?(.*)$");
-    if(orig_field && verbose) {
-        std::cout<<"Overwriting original maintainer: "<< *orig_field <<"\n";
-    }
-
-    if(verbose) {
-        std::cout<<"The original maintainer is: "<< om <<"\n";
-        std::cout<<"Resetting as: "<<UBUNTU_MAINTAINER<<"\n";
-    }
-
-    // set original maint
-    if(orig_field) {
-        // pattern to replace original maint
-        std::regex orig_re("^(?:[XSBC]*-)?Original-Maintainer:.*$", std::regex_constants::multiline);
-        c = std::regex_replace(c, orig_re, "XSBC-Original-Maintainer: " + om);
-    } else {
-        // insert after Maintainer line
-        std::regex maint_re("^(Maintainer:.*)$", std::regex_constants::multiline);
-        c = std::regex_replace(c, maint_re, "$1\nXSBC-Original-Maintainer: " + om);
-    }
-
-    // now set maint
-    {
-        std::regex maint_re("^Maintainer:\\s?.*$", std::regex_constants::multiline);
-        c = std::regex_replace(c, maint_re, "Maintainer: " + std::string(UBUNTU_MAINTAINER));
-    }
-
-    write_file(control_file, c);
-}
-
-void update_maintainer(const std::string &debian_directory, bool verbose) {
-    fs::path debian_dir(debian_directory);
-    auto control_file = find_control_file(debian_dir);
-    if(!control_file) {
-        throw MaintainerUpdateException("No control file found");
-    }
-    fs::path changelog = find_changelog_file(debian_dir);
-    if(xsbc_managed_by_rules(debian_dir)) {
-        if(verbose) {
-            std::cout<<"XSBC-Original is managed by rules. Doing nothing.\n";
-        }
-        return;
-    }
-
-    std::string distribution = get_distribution(changelog);
-
-    update_maintainer_file(*control_file, distribution, verbose);
-}
-
-int main(int argc, char** argv) {
+int main(int argc, char** argv[]) {
     if(argc < 2) {
         std::cerr << "Usage: update-maintainer <debian_directory> [--verbose]" << std::endl;
         return 1;
@@ -232,7 +36,7 @@ int main(int argc, char** argv) {
         if(verbose) {
             std::cout << "Maintainer updated successfully." << std::endl;
         }
-    } catch(const MaintainerUpdateException& e) {
+    } catch(const std::exception& e) {
         std::cerr << "Error: " << e.what() << std::endl;
         return 1;
     }