diff --git a/src/jrd/DatabaseSnapshot.cpp b/src/jrd/DatabaseSnapshot.cpp
index 2a1ba67e73..e58c413a34 100644
--- a/src/jrd/DatabaseSnapshot.cpp
+++ b/src/jrd/DatabaseSnapshot.cpp
@@ -403,19 +403,27 @@ int DatabaseSnapshot::blockingAst(void* ast_object)
 	if (!(dbb->dbb_ast_flags & DBB_monitor_off))
 	{
 		// Write the data to the shared memory
-		try
+		if (!(dbb->dbb_flags & DBB_not_in_use))
 		{
-			dumpData(tdbb, true);
-		}
-		catch (const Exception& ex)
-		{
-			ISC_STATUS_ARRAY status;
-			ex.stuff_exception(status);
-			gds__log_status("Cannot dump the monitoring data", status);
+			try
+			{
+				dumpData(tdbb, true);
+			}
+			catch (const Exception& ex)
+			{
+				ISC_STATUS_ARRAY status;
+				ex.stuff_exception(status);
+				gds__log_status("Cannot dump the monitoring data", status);
+			}
 		}
 
-		// Release the lock and mark dbb as requesting a new one
-		LCK_release(tdbb, lock);
+		// Release the lock, if feasible
+		if (!(dbb->dbb_flags & DBB_monitor_locking))
+		{
+			LCK_release(tdbb, lock);
+		}
+
+		// Mark dbb as requesting a new lock
 		dbb->dbb_ast_flags |= DBB_monitor_off;
 	}
 
diff --git a/src/jrd/jrd.cpp b/src/jrd/jrd.cpp
index 5556eb4a79..cef274a2a0 100644
--- a/src/jrd/jrd.cpp
+++ b/src/jrd/jrd.cpp
@@ -4692,7 +4692,9 @@ bool JRD_reschedule(thread_db* tdbb, SLONG quantum, bool punt)
 	if (dbb->dbb_ast_flags & DBB_monitor_off) 
 	{
 		dbb->dbb_ast_flags &= ~DBB_monitor_off;
+		dbb->dbb_flags |= DBB_monitor_locking;
 		LCK_lock(tdbb, dbb->dbb_monitor_lock, LCK_SR, LCK_WAIT);
+		dbb->dbb_flags &= ~DBB_monitor_locking;
 
 		// While waiting for return from LCK_lock call above the blocking AST (see 
 		// DatabaseSnapshot::blockingAst) was called and set DBB_monitor_off flag 
@@ -5029,7 +5031,9 @@ static ISC_STATUS check_database(thread_db* tdbb, Attachment* attachment, ISC_ST
 	if (dbb->dbb_ast_flags & DBB_monitor_off) 
 	{
 		dbb->dbb_ast_flags &= ~DBB_monitor_off;
+		dbb->dbb_flags |= DBB_monitor_locking;
 		LCK_lock(tdbb, dbb->dbb_monitor_lock, LCK_SR, LCK_WAIT);
+		dbb->dbb_flags &= ~DBB_monitor_locking;
 
 		if (dbb->dbb_ast_flags & DBB_monitor_off)
 			LCK_release(tdbb, dbb->dbb_monitor_lock);
diff --git a/src/jrd/jrd.h b/src/jrd/jrd.h
index bc82ada784..8811d4b044 100644
--- a/src/jrd/jrd.h
+++ b/src/jrd/jrd.h
@@ -389,6 +389,8 @@ const ULONG DBB_gc_background		= 0x1000000L;	// background garbage collection by
 #if (defined DEV_BUILD && !defined MULTI_THREAD)
 const ULONG DBB_exec_statement		= 0x2000000L;	// execute statement runs against database
 #endif
+const ULONG DBB_monitor_locking		= 0x4000000L;	// monitoring lock is being acquired
+
 //
 // dbb_ast_flags
 //