diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 81f616c..68a81ed 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -178,16 +178,6 @@
     UpdateState ProcessUpdateState(const std::function<bool()>& callback = {},
                                    const std::function<bool()>& before_cancel = {});
 
-    // Initiate the merge if necessary, then wait for the merge to finish.
-    // See InitiateMerge() and ProcessUpdateState() for details.
-    // Returns:
-    //   - None if no merge to initiate
-    //   - Unverified if called on the source slot
-    //   - MergeCompleted if merge is completed
-    //   - other states indicating an error has occurred
-    UpdateState InitiateMergeAndWait(SnapshotMergeReport* report = nullptr,
-                                     const std::function<bool()>& before_cancel = {});
-
     // Find the status of the current update, if any.
     //
     // |progress| depends on the returned status:
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 154b5d7..ff63f63 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -2495,68 +2495,6 @@
     return AutoUnmountDevice::New(device_->GetMetadataDir());
 }
 
-UpdateState SnapshotManager::InitiateMergeAndWait(SnapshotMergeReport* stats_report,
-                                                  const std::function<bool()>& before_cancel) {
-    {
-        auto lock = LockExclusive();
-        // Sync update state from file with bootloader.
-        if (!WriteUpdateState(lock.get(), ReadUpdateState(lock.get()))) {
-            LOG(WARNING) << "Unable to sync write update state, fastboot may "
-                         << "reject / accept wipes incorrectly!";
-        }
-    }
-
-    auto merge_stats = SnapshotMergeStats::GetInstance(*this);
-
-    unsigned int last_progress = 0;
-    auto callback = [&]() -> bool {
-        double progress;
-        GetUpdateState(&progress);
-        if (last_progress < static_cast<unsigned int>(progress)) {
-            last_progress = progress;
-            LOG(INFO) << "Waiting for merge to complete: " << last_progress << "%.";
-        }
-        return true;  // continue
-    };
-
-    LOG(INFO) << "Waiting for any previous merge request to complete. "
-              << "This can take up to several minutes.";
-    merge_stats->Start();
-    auto state = ProcessUpdateState(callback, before_cancel);
-    merge_stats->set_state(state);
-    if (state == UpdateState::None) {
-        LOG(INFO) << "Can't find any snapshot to merge.";
-        return state;
-    }
-    if (state == UpdateState::Unverified) {
-        if (GetCurrentSlot() != Slot::Target) {
-            LOG(INFO) << "Cannot merge until device reboots.";
-            return state;
-        }
-
-        if (!InitiateMerge()) {
-            LOG(ERROR) << "Failed to initiate merge.";
-            return state;
-        }
-        // All other states can be handled by ProcessUpdateState.
-        LOG(INFO) << "Waiting for merge to complete. This can take up to several minutes.";
-        last_progress = 0;
-        state = ProcessUpdateState(callback, before_cancel);
-        merge_stats->set_state(state);
-    }
-
-    LOG(INFO) << "Merge finished with state \"" << state << "\".";
-    if (stats_report) {
-        auto result = merge_stats->Finish();
-        if (result) {
-            *stats_report = result->report();
-        } else {
-            LOG(WARNING) << "SnapshotMergeStatus::Finish failed.";
-        }
-    }
-    return state;
-}
-
 bool SnapshotManager::HandleImminentDataWipe(const std::function<void()>& callback) {
     if (!device_->IsRecovery()) {
         LOG(ERROR) << "Data wipes are only allowed in recovery.";
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index 7d16ec2..855451d 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -1027,7 +1027,8 @@
     }
 
     // Initiate the merge and wait for it to be completed.
-    ASSERT_EQ(UpdateState::MergeCompleted, init->InitiateMergeAndWait());
+    ASSERT_TRUE(init->InitiateMerge());
+    ASSERT_EQ(UpdateState::MergeCompleted, init->ProcessUpdateState());
 
     // Check that the target partitions have the same content after the merge.
     for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {
@@ -1201,7 +1202,8 @@
 
     // Initiate the merge and wait for it to be completed.
     auto new_sm = SnapshotManager::New(new TestDeviceInfo(fake_super, "_b"));
-    ASSERT_EQ(UpdateState::MergeCompleted, new_sm->InitiateMergeAndWait());
+    ASSERT_TRUE(new_sm->InitiateMerge());
+    ASSERT_EQ(UpdateState::MergeCompleted, new_sm->ProcessUpdateState());
 
     // Execute the second update.
     ASSERT_TRUE(new_sm->BeginUpdate());
@@ -1341,7 +1343,8 @@
     ASSERT_GE(fd, 0);
 
     // COW cannot be removed due to open fd, so expect a soft failure.
-    ASSERT_EQ(UpdateState::MergeNeedsReboot, init->InitiateMergeAndWait());
+    ASSERT_TRUE(init->InitiateMerge());
+    ASSERT_EQ(UpdateState::MergeNeedsReboot, init->ProcessUpdateState());
 
     // Simulate shutting down the device.
     fd.reset();
@@ -1354,7 +1357,7 @@
     ASSERT_FALSE(sm->IsSnapshotDevice("sys_b", nullptr));
 
     // Merge should be able to complete now.
-    ASSERT_EQ(UpdateState::MergeCompleted, init->InitiateMergeAndWait());
+    ASSERT_EQ(UpdateState::MergeCompleted, init->ProcessUpdateState());
 }
 
 class MetadataMountedTest : public SnapshotUpdateTest {
@@ -1691,7 +1694,8 @@
 
     // There should be no snapshot to merge.
     auto new_sm = SnapshotManager::New(new TestDeviceInfo(fake_super, flashed_slot_suffix));
-    ASSERT_EQ(UpdateState::Cancelled, new_sm->InitiateMergeAndWait());
+    // update_enigne calls ProcessUpdateState first -- should see Cancelled.
+    ASSERT_EQ(UpdateState::Cancelled, new_sm->ProcessUpdateState());
 
     // Next OTA calls CancelUpdate no matter what.
     ASSERT_TRUE(new_sm->CancelUpdate());
diff --git a/fs_mgr/libsnapshot/snapshotctl.cpp b/fs_mgr/libsnapshot/snapshotctl.cpp
index aa5e9c1..a44de84 100644
--- a/fs_mgr/libsnapshot/snapshotctl.cpp
+++ b/fs_mgr/libsnapshot/snapshotctl.cpp
@@ -24,12 +24,8 @@
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/unique_fd.h>
-#include <android/snapshot/snapshot.pb.h>
-#include <libsnapshot/snapshot.h>
-#include <libsnapshot/snapshot_stats.h>
-#include <statslog.h>
 
-#include "utility.h"
+#include <libsnapshot/snapshot.h>
 
 using namespace std::string_literals;
 
@@ -39,146 +35,22 @@
                  "Actions:\n"
                  "  dump\n"
                  "    Print snapshot states.\n"
-                 "  merge [--logcat] [--log-to-file] [--report] [--dry-run]\n"
-                 "    Initialize merge and wait for it to be completed.\n"
-                 "    If --logcat is specified, log to logcat.\n"
-                 "    If --log-to-file is specified, log to /data/misc/snapshotctl_log/.\n"
-                 "    If both specified, log to both. If none specified, log to stdout.\n"
-                 "    If --report is specified, send merge statistics to statsd.\n"
-                 "    If --dry-run flag, no real merge operation is is triggered, and\n"
-                 "      sample statistics are sent to statsd for testing purpose.\n";
+                 "  merge\n"
+                 "    Deprecated.\n";
     return EX_USAGE;
 }
 
 namespace android {
 namespace snapshot {
 
-static SnapshotMergeReport GetDummySnapshotMergeReport() {
-    SnapshotMergeReport fake_report;
-
-    fake_report.set_state(UpdateState::MergeCompleted);
-    fake_report.set_resume_count(56);
-
-    return fake_report;
-}
-
 bool DumpCmdHandler(int /*argc*/, char** argv) {
     android::base::InitLogging(argv, &android::base::StderrLogger);
     return SnapshotManager::New()->Dump(std::cout);
 }
 
-class FileLogger {
-  public:
-    FileLogger() {
-        static constexpr const char* kLogFilePath = "/data/misc/snapshotctl_log/";
-        std::stringstream ss;
-        ss << kLogFilePath << "snapshotctl." << Now() << ".log";
-        fd_.reset(TEMP_FAILURE_RETRY(
-                open(ss.str().c_str(),
-                     O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NOFOLLOW | O_SYNC, 0644)));
-        if (fd_ == -1) {
-            PLOG(ERROR) << "Cannot open persistent log " << ss.str();
-            return;
-        }
-        // Explicitly chmod again because mode in open() may be masked by umask.
-        if (fchmod(fd_.get(), 0644) == -1) {
-            PLOG(ERROR) << "Cannot chmod 0644 persistent log " << ss.str();
-            return;
-        }
-    }
-    // Copy-contuctor needed to be converted to std::function.
-    FileLogger(const FileLogger& other) { fd_.reset(dup(other.fd_)); }
-    void operator()(android::base::LogId, android::base::LogSeverity, const char* /*tag*/,
-                    const char* /*file*/, unsigned int /*line*/, const char* message) {
-        if (fd_ == -1) return;
-        std::stringstream ss;
-        ss << Now() << ":" << message << "\n";
-        (void)android::base::WriteStringToFd(ss.str(), fd_);
-    }
-
-  private:
-    android::base::unique_fd fd_;
-};
-
-class MergeCmdLogger {
-  public:
-    MergeCmdLogger(int argc, char** argv) {
-        for (int i = 0; i < argc; ++i) {
-            if (argv[i] == "--logcat"s) {
-                loggers_.push_back(android::base::LogdLogger());
-            }
-            if (argv[i] == "--log-to-file"s) {
-                loggers_.push_back(std::move(FileLogger()));
-            }
-        }
-        if (loggers_.empty()) {
-            loggers_.push_back(&android::base::StdioLogger);
-        }
-    }
-    void operator()(android::base::LogId id, android::base::LogSeverity severity, const char* tag,
-                    const char* file, unsigned int line, const char* message) {
-        for (auto&& logger : loggers_) {
-            logger(id, severity, tag, file, line, message);
-        }
-    }
-
-  private:
-    std::vector<android::base::LogFunction> loggers_;
-};
-
-bool MergeCmdHandler(int argc, char** argv) {
-    std::chrono::milliseconds passed_ms;
-
-    bool report_to_statsd = false;
-    bool dry_run = false;
-    for (int i = 2; i < argc; ++i) {
-        if (argv[i] == "--report"s) {
-            report_to_statsd = true;
-        } else if (argv[i] == "--dry-run"s) {
-            dry_run = true;
-        }
-    }
-
-    // 'snapshotctl merge' is stripped away from arguments to
-    // Logger.
-    android::base::InitLogging(argv);
-    android::base::SetLogger(MergeCmdLogger(argc - 2, argv + 2));
-
-    UpdateState state;
-    SnapshotMergeReport merge_report;
-    if (dry_run) {
-        merge_report = GetDummySnapshotMergeReport();
-        state = merge_report.state();
-        passed_ms = std::chrono::milliseconds(1234);
-    } else {
-        auto begin = std::chrono::steady_clock::now();
-
-        state = SnapshotManager::New()->InitiateMergeAndWait(&merge_report);
-
-        // We could wind up in the Unverified state if the device rolled back or
-        // hasn't fully rebooted. Ignore this.
-        if (state == UpdateState::None || state == UpdateState::Unverified) {
-            return true;
-        }
-
-        auto end = std::chrono::steady_clock::now();
-        passed_ms = std::chrono::duration_cast<std::chrono::milliseconds>(end - begin);
-    }
-
-    if (report_to_statsd) {
-        android::util::stats_write(android::util::SNAPSHOT_MERGE_REPORTED,
-                                   static_cast<int32_t>(merge_report.state()),
-                                   static_cast<int64_t>(passed_ms.count()),
-                                   static_cast<int32_t>(merge_report.resume_count()));
-    }
-
-    if (state == UpdateState::MergeCompleted) {
-        LOG(INFO) << "Snapshot merged in " << passed_ms.count() << " ms.";
-        return true;
-    }
-
-    LOG(ERROR) << "Snapshot failed to merge with state \"" << state << "\".";
-
+bool MergeCmdHandler(int /*argc*/, char** argv) {
+    android::base::InitLogging(argv, &android::base::StderrLogger);
+    LOG(WARNING) << "Deprecated. Call update_engine_client --merge instead.";
     return false;
 }