diff --git a/patches/msi-Dummy_Thread/0001-msi-Create-dummy-thread-to-initialize-COM-for-custom.patch b/patches/msi-Dummy_Thread/0001-msi-Create-dummy-thread-to-initialize-COM-for-custom.patch
new file mode 100644
index 00000000..0b531021
--- /dev/null
+++ b/patches/msi-Dummy_Thread/0001-msi-Create-dummy-thread-to-initialize-COM-for-custom.patch
@@ -0,0 +1,99 @@
+From 0763c73423ae069023b54e669b0c9bd648e1f27e Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Michael=20M=C3=BCller?= <michael@fds-team.de>
+Date: Mon, 26 Jun 2017 16:18:09 +0200
+Subject: msi: Create dummy thread to initialize COM for custom actions.
+
+---
+ dlls/msi/action.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 48 insertions(+)
+
+diff --git a/dlls/msi/action.c b/dlls/msi/action.c
+index 16652000ee5..62f01044bf1 100644
+--- a/dlls/msi/action.c
++++ b/dlls/msi/action.c
+@@ -156,6 +156,13 @@ static const WCHAR szValidateProductID[] =
+ static const WCHAR szWriteEnvironmentStrings[] =
+     {'W','r','i','t','e','E','n','v','i','r','o','n','m','e','n','t','S','t','r','i','n','g','s',0};
+ 
++struct dummy_thread
++{
++    HANDLE started;
++    HANDLE stopped;
++    HANDLE thread;
++};
++
+ static void ui_actionstart(MSIPACKAGE *package, LPCWSTR action)
+ {
+     static const WCHAR Query_t[] = 
+@@ -7912,6 +7919,42 @@ static UINT ACTION_PerformActionSequence(MSIPACKAGE *package, UINT seq)
+     return rc;
+ }
+ 
++DWORD WINAPI dummy_thread_proc(void *arg)
++{
++    struct dummy_thread *info = arg;
++    HRESULT hr;
++
++    hr = CoInitializeEx(0, COINIT_MULTITHREADED);
++    if (FAILED(hr)) ERR("CoInitializeEx failed %08x\n", hr);
++
++    SetEvent(info->started);
++    WaitForSingleObject(info->stopped, INFINITE);
++
++    CoUninitialize();
++    return 0;
++}
++
++static void start_dummy_thread(struct dummy_thread *info)
++{
++    if (!(info->started = CreateEventA(NULL, TRUE, FALSE, NULL))) return;
++    if (!(info->stopped = CreateEventA(NULL, TRUE, FALSE, NULL))) return;
++    if (!(info->thread  = CreateThread(NULL, 0, dummy_thread_proc, info, 0, NULL))) return;
++
++    WaitForSingleObject(info->started, INFINITE);
++}
++
++static void stop_dummy_thread(struct dummy_thread *info)
++{
++    if (info->thread)
++    {
++        SetEvent(info->stopped);
++        WaitForSingleObject(info->thread, INFINITE);
++        CloseHandle(info->thread);
++    }
++    if (info->started) CloseHandle(info->started);
++    if (info->stopped) CloseHandle(info->stopped);
++}
++
+ /****************************************************
+  * TOP level entry points
+  *****************************************************/
+@@ -7923,6 +7966,7 @@ UINT MSI_InstallPackage( MSIPACKAGE *package, LPCWSTR szPackagePath,
+     static const WCHAR szAction[] = {'A','C','T','I','O','N',0};
+     static const WCHAR szInstall[] = {'I','N','S','T','A','L','L',0};
+     WCHAR *reinstall, *remove, *patch, *productcode;
++    struct dummy_thread thread_info = {NULL, NULL, NULL};
+     BOOL ui_exists;
+     UINT rc;
+ 
+@@ -7988,6 +8032,8 @@ UINT MSI_InstallPackage( MSIPACKAGE *package, LPCWSTR szPackagePath,
+     msi_adjust_privilege_properties( package );
+     msi_set_context( package );
+ 
++    start_dummy_thread(&thread_info);
++
+     productcode = msi_dup_property( package->db, szProductCode );
+     if (strcmpiW( productcode, package->ProductCode ))
+     {
+@@ -8036,6 +8082,8 @@ UINT MSI_InstallPackage( MSIPACKAGE *package, LPCWSTR szPackagePath,
+     /* finish up running custom actions */
+     ACTION_FinishCustomActions(package);
+ 
++    stop_dummy_thread(&thread_info);
++
+     if (package->need_rollback && !reinstall)
+     {
+         WARN("installation failed, running rollback script\n");
+-- 
+2.13.1
+
diff --git a/patches/msi-Dummy_Thread/definition b/patches/msi-Dummy_Thread/definition
new file mode 100644
index 00000000..6d431ecb
--- /dev/null
+++ b/patches/msi-Dummy_Thread/definition
@@ -0,0 +1 @@
+Fixes: [!18070] Workaround COM/MTA issues due to lack of separate msi custom action process
diff --git a/patches/patchinstall.sh b/patches/patchinstall.sh
index d4dc29c7..5bfe4b1f 100755
--- a/patches/patchinstall.sh
+++ b/patches/patchinstall.sh
@@ -213,6 +213,7 @@ patch_enable_all ()
 	enable_mpr_WNetGetUniversalNameW="$1"
 	enable_mscoree_CorValidateImage="$1"
 	enable_mshtml_HTMLLocation_put_hash="$1"
+	enable_msi_Dummy_Thread="$1"
 	enable_msi_MsiGetDatabaseState="$1"
 	enable_msi_msi_vcl_get_cost="$1"
 	enable_msidb_Implementation="$1"
@@ -885,6 +886,9 @@ patch_enable ()
 		mshtml-HTMLLocation_put_hash)
 			enable_mshtml_HTMLLocation_put_hash="$2"
 			;;
+		msi-Dummy_Thread)
+			enable_msi_Dummy_Thread="$2"
+			;;
 		msi-MsiGetDatabaseState)
 			enable_msi_MsiGetDatabaseState="$2"
 			;;
@@ -5237,6 +5241,21 @@ if test "$enable_mshtml_HTMLLocation_put_hash" -eq 1; then
 	) >> "$patchlist"
 fi
 
+# Patchset msi-Dummy_Thread
+# |
+# | This patchset fixes the following Wine bugs:
+# |   *	[#18070] Workaround COM/MTA issues due to lack of separate msi custom action process
+# |
+# | Modified files:
+# |   *	dlls/msi/action.c
+# |
+if test "$enable_msi_Dummy_Thread" -eq 1; then
+	patch_apply msi-Dummy_Thread/0001-msi-Create-dummy-thread-to-initialize-COM-for-custom.patch
+	(
+		printf '%s\n' '+    { "Michael Müller", "msi: Create dummy thread to initialize COM for custom actions.", 1 },';
+	) >> "$patchlist"
+fi
+
 # Patchset ntdll-NtAllocateUuids
 # |
 # | This patchset fixes the following Wine bugs: