diff --git a/examples/libmbpatcher_test.cpp b/examples/libmbpatcher_test.cpp
index 88a541059..55ff7e178 100644
--- a/examples/libmbpatcher_test.cpp
+++ b/examples/libmbpatcher_test.cpp
@@ -96,9 +96,8 @@ static bool get_device(const char *path, mb::device::Device &device)
     return true;
 }
 
-static void mbp_progress_cb(uint64_t bytes, uint64_t maxBytes, void *userdata)
+static void mbp_progress_cb(uint64_t bytes, uint64_t maxBytes)
 {
-    (void) userdata;
     printf("Current bytes percentage: %.1f\n",
            100.0 * static_cast<double>(bytes) / static_cast<double>(maxBytes));
 }
@@ -140,7 +139,7 @@ int main(int argc, char *argv[]) {
     }
 
     patcher->set_file_info(&fi);
-    bool ret = patcher->patch_file(&mbp_progress_cb, nullptr, nullptr, nullptr);
+    bool ret = patcher->patch_file(&mbp_progress_cb, nullptr, nullptr);
 
     if (!ret) {
         fprintf(stderr, "Error: %d\n", static_cast<int>(patcher->error()));
diff --git a/gui/mainwindow.cpp b/gui/mainwindow.cpp
index bf3a2fe6e..87a69d94f 100644
--- a/gui/mainwindow.cpp
+++ b/gui/mainwindow.cpp
@@ -688,34 +688,16 @@ PatcherTask::PatcherTask(QWidget *parent)
 {
 }
 
-static void progressUpdatedCbWrapper(uint64_t bytes, uint64_t maxBytes,
-                                     void *userData)
-{
-    PatcherTask *task = static_cast<PatcherTask *>(userData);
-    task->progressUpdatedCb(bytes, maxBytes);
-}
-
-static void filesUpdatedCbWrapper(uint64_t files, uint64_t maxFiles,
-                                  void *userData)
-{
-    PatcherTask *task = static_cast<PatcherTask *>(userData);
-    task->filesUpdatedCb(files, maxFiles);
-}
-
-static void detailsUpdatedCbWrapper(const std::string &text, void *userData)
-{
-    PatcherTask *task = static_cast<PatcherTask *>(userData);
-    task->detailsUpdatedCb(text);
-}
-
 void PatcherTask::patch(PatcherPtr patcher, FileInfoPtr info)
 {
+    using namespace std::placeholders;
+
     patcher->set_file_info(info);
 
-    bool ret = patcher->patch_file(&progressUpdatedCbWrapper,
-                                   &filesUpdatedCbWrapper,
-                                   &detailsUpdatedCbWrapper,
-                                   this);
+    bool ret = patcher->patch_file(
+            std::bind(&PatcherTask::progressUpdatedCb, this, _1, _2),
+            std::bind(&PatcherTask::filesUpdatedCb, this, _1, _2),
+            std::bind(&PatcherTask::detailsUpdatedCb, this, _1));
 
     QString newFile(QString::fromStdString(info->output_path()));
 
diff --git a/libmbpatcher/include/mbpatcher/cwrapper/cpatcherinterface.h b/libmbpatcher/include/mbpatcher/cwrapper/cpatcherinterface.h
index 4fc03aa70..fe05b5de4 100644
--- a/libmbpatcher/include/mbpatcher/cwrapper/cpatcherinterface.h
+++ b/libmbpatcher/include/mbpatcher/cwrapper/cpatcherinterface.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2015  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2014-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -35,10 +35,10 @@ MB_EXPORT /* enum ErrorCode */ int mbpatcher_patcher_error(const CPatcher *patch
 MB_EXPORT char * mbpatcher_patcher_id(const CPatcher *patcher);
 MB_EXPORT void mbpatcher_patcher_set_fileinfo(CPatcher *patcher, const CFileInfo *info);
 MB_EXPORT bool mbpatcher_patcher_patch_file(CPatcher *patcher,
-                                            ProgressUpdatedCallback progressCb,
-                                      FilesUpdatedCallback filesCb,
-                                      DetailsUpdatedCallback detailsCb,
-                                      void *userData);
+                                            ProgressUpdatedCallback progress_cb,
+                                      FilesUpdatedCallback files_cb,
+                                      DetailsUpdatedCallback details_cb,
+                                      void *userdata);
 MB_EXPORT void mbpatcher_patcher_cancel_patching(CPatcher *patcher);
 
 
diff --git a/libmbpatcher/include/mbpatcher/patcherinterface.h b/libmbpatcher/include/mbpatcher/patcherinterface.h
index abe35a5aa..de68cec18 100644
--- a/libmbpatcher/include/mbpatcher/patcherinterface.h
+++ b/libmbpatcher/include/mbpatcher/patcherinterface.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2015  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2014-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -19,6 +19,8 @@
 
 #pragma once
 
+#include <functional>
+
 #include "mbcommon/common.h"
 
 #include "mbpatcher/errors.h"
@@ -39,9 +41,9 @@ namespace mb::patcher
 class MB_EXPORT Patcher
 {
 public:
-    typedef void (*ProgressUpdatedCallback) (uint64_t, uint64_t, void *);
-    typedef void (*FilesUpdatedCallback) (uint64_t, uint64_t, void *);
-    typedef void (*DetailsUpdatedCallback) (const std::string &, void *);
+    using ProgressUpdatedCallback = std::function<void(uint64_t, uint64_t)>;
+    using FilesUpdatedCallback = std::function<void(uint64_t, uint64_t)>;
+    using DetailsUpdatedCallback = std::function<void(const std::string &)>;
 
     virtual ~Patcher() {}
 
@@ -73,12 +75,10 @@ class MB_EXPORT Patcher
      * \param progress_cb Callback for receiving current progress values
      * \param files_cb Callback for receiving current files count
      * \param details_cb Callback for receiving detailed progress text
-     * \param userdata Pointer to pass to callback functions
      */
-    virtual bool patch_file(ProgressUpdatedCallback progress_cb,
-                            FilesUpdatedCallback files_cb,
-                            DetailsUpdatedCallback details_cb,
-                            void *userdata) = 0;
+    virtual bool patch_file(const ProgressUpdatedCallback &progress_cb,
+                            const FilesUpdatedCallback &files_cb,
+                            const DetailsUpdatedCallback &details_cb) = 0;
 
     /*!
      * \brief Cancel the patching of a file
diff --git a/libmbpatcher/include/mbpatcher/patchers/odinpatcher.h b/libmbpatcher/include/mbpatcher/patchers/odinpatcher.h
index 1f0515213..4eead0bd2 100644
--- a/libmbpatcher/include/mbpatcher/patchers/odinpatcher.h
+++ b/libmbpatcher/include/mbpatcher/patchers/odinpatcher.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2017  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2015-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -55,10 +55,9 @@ class OdinPatcher : public Patcher
     // Patching
     void set_file_info(const FileInfo * const info) override;
 
-    bool patch_file(ProgressUpdatedCallback progress_cb,
-                    FilesUpdatedCallback files_cb,
-                    DetailsUpdatedCallback details_cb,
-                    void *userdata) override;
+    bool patch_file(const ProgressUpdatedCallback &progress_cb,
+                    const FilesUpdatedCallback &files_cb,
+                    const DetailsUpdatedCallback &details_cb) override;
 
     void cancel_patching() override;
 
@@ -85,9 +84,8 @@ class OdinPatcher : public Patcher
     std::unordered_set<std::string> m_added_files;
 
     // Callbacks
-    OdinPatcher::ProgressUpdatedCallback m_progress_cb;
-    OdinPatcher::DetailsUpdatedCallback m_details_cb;
-    void *m_userdata;
+    const ProgressUpdatedCallback *m_progress_cb;
+    const DetailsUpdatedCallback *m_details_cb;
 
     // Patching
     archive *m_a_input;
diff --git a/libmbpatcher/include/mbpatcher/patchers/ramdiskupdater.h b/libmbpatcher/include/mbpatcher/patchers/ramdiskupdater.h
index bfb930c5b..856d10e3e 100644
--- a/libmbpatcher/include/mbpatcher/patchers/ramdiskupdater.h
+++ b/libmbpatcher/include/mbpatcher/patchers/ramdiskupdater.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2017  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2014-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -47,10 +47,9 @@ class RamdiskUpdater : public Patcher
     // Patching
     void set_file_info(const FileInfo * const info) override;
 
-    bool patch_file(ProgressUpdatedCallback progress_cb,
-                    FilesUpdatedCallback files_cb,
-                    DetailsUpdatedCallback details_cb,
-                    void *userdata) override;
+    bool patch_file(const ProgressUpdatedCallback &progress_cb,
+                    const FilesUpdatedCallback &files_cb,
+                    const DetailsUpdatedCallback &details_cb) override;
 
     void cancel_patching() override;
 
diff --git a/libmbpatcher/include/mbpatcher/patchers/zippatcher.h b/libmbpatcher/include/mbpatcher/patchers/zippatcher.h
index 1d2a4a2cc..f91812bf8 100644
--- a/libmbpatcher/include/mbpatcher/patchers/zippatcher.h
+++ b/libmbpatcher/include/mbpatcher/patchers/zippatcher.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2017  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2014-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -50,10 +50,9 @@ class ZipPatcher : public Patcher
     // Patching
     void set_file_info(const FileInfo * const info) override;
 
-    bool patch_file(ProgressUpdatedCallback progress_cb,
-                    FilesUpdatedCallback files_cb,
-                    DetailsUpdatedCallback details_cb,
-                    void *userdata) override;
+    bool patch_file(const ProgressUpdatedCallback &progress_cb,
+                    const FilesUpdatedCallback &files_cb,
+                    const DetailsUpdatedCallback &details_cb) override;
 
     void cancel_patching() override;
 
@@ -73,10 +72,9 @@ class ZipPatcher : public Patcher
     ErrorCode m_error;
 
     // Callbacks
-    ProgressUpdatedCallback m_progress_cb;
-    FilesUpdatedCallback m_files_cb;
-    DetailsUpdatedCallback m_details_cb;
-    void *m_userdata;
+    const ProgressUpdatedCallback *m_progress_cb;
+    const FilesUpdatedCallback *m_files_cb;
+    const DetailsUpdatedCallback *m_details_cb;
 
     // Patching
     ZipCtx *m_z_input = nullptr;
@@ -98,7 +96,7 @@ class ZipPatcher : public Patcher
     void update_files(uint64_t files, uint64_t max_files);
     void update_details(const std::string &msg);
 
-    static void la_progress_cb(uint64_t bytes, void *userdata);
+    void la_progress_cb(uint64_t bytes);
 };
 
 }
diff --git a/libmbpatcher/include/mbpatcher/private/miniziputils.h b/libmbpatcher/include/mbpatcher/private/miniziputils.h
index 5b2e295a9..e025dc525 100644
--- a/libmbpatcher/include/mbpatcher/private/miniziputils.h
+++ b/libmbpatcher/include/mbpatcher/private/miniziputils.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2017  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2014-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -19,6 +19,7 @@
 
 #pragma once
 
+#include <functional>
 #include <string>
 #include <vector>
 
@@ -61,13 +62,11 @@ class MinizipUtils
     static bool copy_file_raw(void *source_handle,
                               void *target_handle,
                               const std::string &name,
-                              void (*cb)(uint64_t bytes, void *),
-                              void *userdata);
+                              const std::function<void(uint64_t bytes)> &cb);
 
     static bool read_to_memory(void *handle,
                                std::vector<unsigned char> &output,
-                               void (*cb)(uint64_t bytes, void *),
-                               void *userdata);
+                               const std::function<void(uint64_t bytes)> &cb);
 
     static bool extract_file(void *handle,
                              const std::string &directory);
diff --git a/libmbpatcher/src/cwrapper/cpatcherinterface.cpp b/libmbpatcher/src/cwrapper/cpatcherinterface.cpp
index 70e7b704f..c19e41187 100644
--- a/libmbpatcher/src/cwrapper/cpatcherinterface.cpp
+++ b/libmbpatcher/src/cwrapper/cpatcherinterface.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2015  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2014-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -54,39 +54,6 @@
 extern "C"
 {
 
-struct CallbackWrapper
-{
-    ProgressUpdatedCallback progress_cb;
-    FilesUpdatedCallback files_cb;
-    DetailsUpdatedCallback details_cb;
-    void *userdata;
-};
-
-static void progress_cb_wrapper(uint64_t bytes, uint64_t max_bytes,
-                                void *userdata)
-{
-    CallbackWrapper *wrapper = reinterpret_cast<CallbackWrapper *>(userdata);
-    if (wrapper->progress_cb != nullptr) {
-        wrapper->progress_cb(bytes, max_bytes, wrapper->userdata);
-    }
-}
-
-static void files_cb_wrapper(uint64_t files, uint64_t max_files, void *userdata)
-{
-    CallbackWrapper *wrapper = reinterpret_cast<CallbackWrapper *>(userdata);
-    if (wrapper->files_cb) {
-        wrapper->files_cb(files, max_files, userdata);
-    }
-}
-
-static void details_cb_wrapper(const std::string &text, void *userdata)
-{
-    CallbackWrapper *wrapper = reinterpret_cast<CallbackWrapper *>(userdata);
-    if (wrapper->details_cb) {
-        wrapper->details_cb(text.c_str(), wrapper->userdata);
-    }
-}
-
 /*!
  * \brief Get the error information
  *
@@ -143,30 +110,39 @@ void mbpatcher_patcher_set_fileinfo(CPatcher *patcher, const CFileInfo *info)
  * \brief Start patching the file
  *
  * \param patcher CPatcher object
- * \param progressCb Callback for receiving current progress value
- * \param detailsCb Callback for receiving detailed progress text
- * \param userData Pointer to pass to callback functions
+ * \param progress_cb Callback for receiving current progress value
+ * \param files_cb Callback for receiving current files count
+ * \param details_cb Callback for receiving detailed progress text
+ * \param userdata Pointer to pass to callback functions
  * \return true on success, otherwise false (and error set appropriately)
  *
  * \sa Patcher::patchFile()
  */
 bool mbpatcher_patcher_patch_file(CPatcher *patcher,
-                                  ProgressUpdatedCallback progressCb,
-                                  FilesUpdatedCallback filesCb,
-                                  DetailsUpdatedCallback detailsCb,
-                                  void *userData)
+                                  ProgressUpdatedCallback progress_cb,
+                                  FilesUpdatedCallback files_cb,
+                                  DetailsUpdatedCallback details_cb,
+                                  void *userdata)
 {
     CASTP(patcher);
 
-    CallbackWrapper wrapper;
-    wrapper.progress_cb = progressCb;
-    wrapper.files_cb = filesCb;
-    wrapper.details_cb = detailsCb;
-    wrapper.userdata = userData;
-
-    return p->patch_file(&progress_cb_wrapper, &files_cb_wrapper,
-                         &details_cb_wrapper,
-                         reinterpret_cast<void *>(&wrapper));
+    return p->patch_file(
+        [&](uint64_t bytes, uint64_t max_bytes) {
+            if (progress_cb) {
+                progress_cb(bytes, max_bytes, userdata);
+            }
+        },
+        [&](uint64_t files, uint64_t max_files) {
+            if (files_cb) {
+                files_cb(files, max_files, userdata);
+            }
+        },
+        [&](const std::string &text) {
+            if (details_cb) {
+                details_cb(text.c_str(), userdata);
+            }
+        }
+    );
 }
 
 /*!
diff --git a/libmbpatcher/src/patchers/odinpatcher.cpp b/libmbpatcher/src/patchers/odinpatcher.cpp
index 6774af50e..667e0f44a 100644
--- a/libmbpatcher/src/patchers/odinpatcher.cpp
+++ b/libmbpatcher/src/patchers/odinpatcher.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2017  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2015-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -73,7 +73,6 @@ OdinPatcher::OdinPatcher(PatcherConfig &pc)
     , m_added_files()
     , m_progress_cb()
     , m_details_cb()
-    , m_userdata()
     , m_a_input(nullptr)
     , m_z_output(nullptr)
 {
@@ -101,10 +100,9 @@ void OdinPatcher::cancel_patching()
     m_cancelled = true;
 }
 
-bool OdinPatcher::patch_file(ProgressUpdatedCallback progress_cb,
-                             FilesUpdatedCallback files_cb,
-                             DetailsUpdatedCallback details_cb,
-                             void *userdata)
+bool OdinPatcher::patch_file(const ProgressUpdatedCallback &progress_cb,
+                             const FilesUpdatedCallback &files_cb,
+                             const DetailsUpdatedCallback &details_cb)
 {
     (void) files_cb;
 
@@ -112,9 +110,8 @@ bool OdinPatcher::patch_file(ProgressUpdatedCallback progress_cb,
 
     assert(m_info != nullptr);
 
-    m_progress_cb = progress_cb;
-    m_details_cb = details_cb;
-    m_userdata = userdata;
+    m_progress_cb = &progress_cb;
+    m_details_cb = &details_cb;
 
     m_old_bytes = 0;
     m_bytes = 0;
@@ -124,7 +121,6 @@ bool OdinPatcher::patch_file(ProgressUpdatedCallback progress_cb,
 
     m_progress_cb = nullptr;
     m_details_cb = nullptr;
-    m_userdata = nullptr;
 
     if (m_a_input != nullptr) {
         close_input_archive();
@@ -607,7 +603,7 @@ bool OdinPatcher::close_output_archive()
 
 void OdinPatcher::update_progress(uint64_t bytes, uint64_t max_bytes)
 {
-    if (m_progress_cb) {
+    if (m_progress_cb && *m_progress_cb) {
         bool should_call = true;
         if (max_bytes > 0) {
             // Rate limit... call back only if percentage exceeds 0.01%
@@ -620,7 +616,7 @@ void OdinPatcher::update_progress(uint64_t bytes, uint64_t max_bytes)
             }
         }
         if (should_call) {
-            m_progress_cb(bytes, max_bytes, m_userdata);
+            (*m_progress_cb)(bytes, max_bytes);
             m_old_bytes = bytes;
         }
     }
@@ -628,8 +624,8 @@ void OdinPatcher::update_progress(uint64_t bytes, uint64_t max_bytes)
 
 void OdinPatcher::update_details(const std::string &msg)
 {
-    if (m_details_cb) {
-        m_details_cb(msg, m_userdata);
+    if (m_details_cb && *m_details_cb) {
+        (*m_details_cb)(msg);
     }
 }
 
diff --git a/libmbpatcher/src/patchers/ramdiskupdater.cpp b/libmbpatcher/src/patchers/ramdiskupdater.cpp
index 3bb6596e6..b44a63661 100644
--- a/libmbpatcher/src/patchers/ramdiskupdater.cpp
+++ b/libmbpatcher/src/patchers/ramdiskupdater.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2017  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2014-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -71,15 +71,13 @@ void RamdiskUpdater::cancel_patching()
     m_cancelled = true;
 }
 
-bool RamdiskUpdater::patch_file(ProgressUpdatedCallback progress_cb,
-                                FilesUpdatedCallback files_cb,
-                                DetailsUpdatedCallback details_cb,
-                                void *userdata)
+bool RamdiskUpdater::patch_file(const ProgressUpdatedCallback &progress_cb,
+                                const FilesUpdatedCallback &files_cb,
+                                const DetailsUpdatedCallback &details_cb)
 {
     (void) progress_cb;
     (void) files_cb;
     (void) details_cb;
-    (void) userdata;
 
     m_cancelled = false;
 
diff --git a/libmbpatcher/src/patchers/zippatcher.cpp b/libmbpatcher/src/patchers/zippatcher.cpp
index 1b2167555..0b56384a6 100644
--- a/libmbpatcher/src/patchers/zippatcher.cpp
+++ b/libmbpatcher/src/patchers/zippatcher.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2017  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2014-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -62,7 +62,6 @@ ZipPatcher::ZipPatcher(PatcherConfig &pc)
     , m_progress_cb(nullptr)
     , m_files_cb(nullptr)
     , m_details_cb(nullptr)
-    , m_userdata(nullptr)
     , m_z_input(nullptr)
     , m_z_output(nullptr)
 {
@@ -90,19 +89,17 @@ void ZipPatcher::cancel_patching()
     m_cancelled = true;
 }
 
-bool ZipPatcher::patch_file(ProgressUpdatedCallback progress_cb,
-                            FilesUpdatedCallback files_cb,
-                            DetailsUpdatedCallback details_cb,
-                            void *userdata)
+bool ZipPatcher::patch_file(const ProgressUpdatedCallback &progress_cb,
+                            const FilesUpdatedCallback &files_cb,
+                            const DetailsUpdatedCallback &details_cb)
 {
     m_cancelled = false;
 
     assert(m_info != nullptr);
 
-    m_progress_cb = progress_cb;
-    m_files_cb = files_cb;
-    m_details_cb = details_cb;
-    m_userdata = userdata;
+    m_progress_cb = &progress_cb;
+    m_files_cb = &files_cb;
+    m_details_cb = &details_cb;
 
     m_bytes = 0;
     m_max_bytes = 0;
@@ -114,7 +111,6 @@ bool ZipPatcher::patch_file(ProgressUpdatedCallback progress_cb,
     m_progress_cb = nullptr;
     m_files_cb = nullptr;
     m_details_cb = nullptr;
-    m_userdata = nullptr;
 
     for (auto *p : m_auto_patchers) {
         m_pc.destroy_auto_patcher(p);
@@ -313,6 +309,8 @@ bool ZipPatcher::patch_zip()
 bool ZipPatcher::pass1(const std::string &temporary_dir,
                        const std::unordered_set<std::string> &exclude)
 {
+    using namespace std::placeholders;
+
     void *h_in = MinizipUtils::ctx_get_zip_handle(m_z_input);
     void *h_out = MinizipUtils::ctx_get_zip_handle(m_z_output);
 
@@ -353,8 +351,8 @@ bool ZipPatcher::pass1(const std::string &temporary_dir,
                 cur_file = "META-INF/com/google/android/update-binary.orig";
             }
 
-            if (!MinizipUtils::copy_file_raw(
-                    h_in, h_out, cur_file, &la_progress_cb, this)) {
+            if (!MinizipUtils::copy_file_raw(h_in, h_out, cur_file,
+                    std::bind(&ZipPatcher::la_progress_cb, this, _1))) {
                 LOGW("minizip: Failed to copy raw data: %s", cur_file.c_str());
                 m_error = ErrorCode::ArchiveWriteDataError;
                 return false;
@@ -487,29 +485,28 @@ void ZipPatcher::close_output_archive()
 
 void ZipPatcher::update_progress(uint64_t bytes, uint64_t max_bytes)
 {
-    if (m_progress_cb) {
-        m_progress_cb(bytes, max_bytes, m_userdata);
+    if (m_progress_cb && *m_progress_cb) {
+        (*m_progress_cb)(bytes, max_bytes);
     }
 }
 
 void ZipPatcher::update_files(uint64_t files, uint64_t max_files)
 {
-    if (m_files_cb) {
-        m_files_cb(files, max_files, m_userdata);
+    if (m_files_cb && *m_files_cb) {
+        (*m_files_cb)(files, max_files);
     }
 }
 
 void ZipPatcher::update_details(const std::string &msg)
 {
-    if (m_details_cb) {
-        m_details_cb(msg, m_userdata);
+    if (m_details_cb && *m_details_cb) {
+        (*m_details_cb)(msg);
     }
 }
 
-void ZipPatcher::la_progress_cb(uint64_t bytes, void *userdata)
+void ZipPatcher::la_progress_cb(uint64_t bytes)
 {
-    auto *p = static_cast<ZipPatcher *>(userdata);
-    p->update_progress(p->m_bytes + bytes, p->m_max_bytes);
+    update_progress(m_bytes + bytes, m_max_bytes);
 }
 
 std::string ZipPatcher::create_info_prop(const std::string &rom_id)
diff --git a/libmbpatcher/src/private/miniziputils.cpp b/libmbpatcher/src/private/miniziputils.cpp
index f4c9e12b4..e610a14eb 100644
--- a/libmbpatcher/src/private/miniziputils.cpp
+++ b/libmbpatcher/src/private/miniziputils.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2017  Andrew Gunnerson <andrewgunnerson@gmail.com>
+ * Copyright (C) 2014-2018  Andrew Gunnerson <andrewgunnerson@gmail.com>
  *
  * This file is part of DualBootPatcher
  *
@@ -212,8 +212,7 @@ ErrorCode MinizipUtils::archive_stats(const std::string &path,
 bool MinizipUtils::copy_file_raw(void *source_handle,
                                  void *target_handle,
                                  const std::string &name,
-                                 void (*cb)(uint64_t bytes, void *),
-                                 void *userdata)
+                                 const std::function<void(uint64_t bytes)> &cb)
 {
     mz_zip_file *file_info;
 
@@ -264,8 +263,7 @@ bool MinizipUtils::copy_file_raw(void *source_handle,
             ratio = static_cast<double>(bytes)
                     / static_cast<double>(file_info->compressed_size);
             cb(static_cast<uint64_t>(
-                    ratio * static_cast<double>(file_info->uncompressed_size)),
-               userdata);
+                    ratio * static_cast<double>(file_info->uncompressed_size)));
         }
 
         int n_written = mz_zip_entry_write(
@@ -302,8 +300,7 @@ bool MinizipUtils::copy_file_raw(void *source_handle,
 
 bool MinizipUtils::read_to_memory(void *handle,
                                   std::vector<unsigned char> &output,
-                                  void (*cb)(uint64_t bytes, void *),
-                                  void *userdata)
+                                  const std::function<void(uint64_t bytes)> &cb)
 {
     mz_zip_file *file_info;
 
@@ -331,8 +328,7 @@ bool MinizipUtils::read_to_memory(void *handle,
 
     while ((n = mz_zip_entry_read(handle, buf, sizeof(buf))) > 0) {
         if (cb) {
-            cb(static_cast<uint64_t>(data.size()) + static_cast<uint64_t>(n),
-               userdata);
+            cb(static_cast<uint64_t>(data.size()) + static_cast<uint64_t>(n));
         }
 
         data.insert(data.end(), buf, buf + n);