diff --git a/ide/lazarusidestrconsts.pas b/ide/lazarusidestrconsts.pas
index 0a318ec3a3..c5d4e84978 100644
--- a/ide/lazarusidestrconsts.pas
+++ b/ide/lazarusidestrconsts.pas
@@ -160,6 +160,9 @@ resourcestring
     'directory where Lazarus searches for config template files. Default is "%s".';
   lisFileWhereDebugOutputIsWritten =
     'File where debug output is written to. Default is write to the console.';
+  lisDebugLogCloseOptDescr =
+    'Close log file between writes. Prevents loss of unsaved data when the IDE crashes. '+
+    'By default, writes are buffered by the OS for performance.';
   lisSkipStartupChecks = 'Skip selected checks at startup. Valid options are:';
   lisGroupsForDebugOutput = 'Enable or disable groups of debug output. ' +
     'Valid options are:';
diff --git a/ide/main.pp b/ide/main.pp
index f869955017..e0e8abf54f 100644
--- a/ide/main.pp
+++ b/ide/main.pp
@@ -1125,6 +1125,7 @@ var
     AddCmdLineParamDesc(result, ['--verbose'], lisBeMoreVerboseCanBeGivenMultipleTimes);
     // debug file
     AddCmdLineParamDesc(result, [DebugLogOpt + '<file>'], lisFileWhereDebugOutputIsWritten);
+    AddCmdLineParamDesc(result, [DebugLogCloseLogOpt], lisDebugLogCloseOptDescr);
     // debug groups (sorted)
     lLogGroups := TStringList.Create;
     for i := 0 to DebugLogger.LogGroupList.Count - 1 do