diff --git a/src/jrd/cch.cpp b/src/jrd/cch.cpp
index ab2e77d953..b39d663da2 100644
--- a/src/jrd/cch.cpp
+++ b/src/jrd/cch.cpp
@@ -3982,7 +3982,6 @@ static THREAD_ENTRY_DECLARE cache_reader(THREAD_ENTRY_PARAM arg)
 	tdbb->setDatabase(dbb);
 	Attachment* const attachment = Attachment::create(dbb);
 	tdbb->setAttachment(attachment);
-	attachment->att_mutex.enter();
 	attachment->att_filename = dbb->dbb_filename;
 	Jrd::ContextPoolHolder context(tdbb, dbb->dbb_bufferpool);
 
@@ -4146,7 +4145,6 @@ static THREAD_ENTRY_DECLARE cache_writer(THREAD_ENTRY_PARAM arg)
 	tdbb->setDatabase(dbb);
 	Attachment* const attachment = Attachment::create(dbb);
 	tdbb->setAttachment(attachment);
-	attachment->att_mutex.enter();
 	attachment->att_filename = dbb->dbb_filename;
 	Jrd::ContextPoolHolder context(tdbb, dbb->dbb_bufferpool);
 
diff --git a/src/jrd/jrd.cpp b/src/jrd/jrd.cpp
index 1a34aeb7e3..2b962301a2 100644
--- a/src/jrd/jrd.cpp
+++ b/src/jrd/jrd.cpp
@@ -807,7 +807,6 @@ ISC_STATUS GDS_ATTACH_DATABASE(ISC_STATUS* user_status,
 	attachment->att_remote_address = options.dpb_remote_address;
 	attachment->att_remote_pid = options.dpb_remote_pid;
 	attachment->att_remote_process = options.dpb_remote_process;
-	attachment->att_mutex.enter();
 	attachment->att_next = dbb->dbb_attachments;
 
 	dbb->dbb_attachments = attachment;
@@ -1968,6 +1967,7 @@ ISC_STATUS GDS_CREATE_DATABASE(ISC_STATUS* user_status,
 	databases_mutex->leave();
 
 	*handle = attachment;
+	attachment->att_mutex.leave();
 
 	}	// try
 	catch (const DelayFailedLogin& ex)
@@ -4947,6 +4947,7 @@ Attachment::Attachment(MemoryPool* pool, Database* dbb)
 	att_remote_process(*pool),
 	att_dsql_cache(*pool)
 {
+	att_mutex.enter();
 }
 
 
diff --git a/src/jrd/vio.cpp b/src/jrd/vio.cpp
index 3f82801014..4155c2efc9 100644
--- a/src/jrd/vio.cpp
+++ b/src/jrd/vio.cpp
@@ -3897,7 +3897,6 @@ static THREAD_ENTRY_DECLARE garbage_collector(THREAD_ENTRY_PARAM arg)
 
 		Attachment* const attachment = Attachment::create(dbb);
 		tdbb->setAttachment(attachment);
-		attachment->att_mutex.enter();
 		attachment->att_filename = dbb->dbb_filename;
 		attachment->att_flags = ATT_garbage_collector;