diff --git a/.gitattributes b/.gitattributes
index 3e4b783c48..0ac2a9ae5a 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -6220,6 +6220,8 @@ test/customdrawn/lazdialogs_test.res -text
 test/customdrawn/mainform.lfm svneol=native#text/plain
 test/customdrawn/mainform.pas svneol=native#text/plain
 test/hello.ahk svneol=native#text/plain
+test/lazutils/TestLazLogger.lpr svneol=native#text/pascal
+test/lazutils/testlazloggercase.pas svneol=native#text/pascal
 test/lazutils/testpaswstring.lpi svneol=native#text/plain
 test/lazutils/testpaswstring.pas svneol=native#text/plain
 test/lazutils/testunicode.lpi svneol=native#text/plain
diff --git a/test/lazutils/TestLazLogger.lpr b/test/lazutils/TestLazLogger.lpr
new file mode 100644
index 0000000000..673af2ee3b
--- /dev/null
+++ b/test/lazutils/TestLazLogger.lpr
@@ -0,0 +1,15 @@
+program TestLazLogger;
+
+{$mode objfpc}{$H+}
+
+uses
+  Interfaces, Forms, GuiTestRunner, TestLazLoggerCase;
+
+{$R *.res}
+
+begin
+  Application.Initialize;
+  Application.CreateForm(TGuiTestRunner, TestRunner);
+  Application.Run;
+end.
+
diff --git a/test/lazutils/testlazloggercase.pas b/test/lazutils/testlazloggercase.pas
new file mode 100644
index 0000000000..242dce6eab
--- /dev/null
+++ b/test/lazutils/testlazloggercase.pas
@@ -0,0 +1,130 @@
+unit TestLazLoggerCase;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, fpcunit, testutils, testregistry, LazLogger;
+
+type
+
+  { TTestLazLogger }
+
+  TTestLazLogger = class(TTestCase)
+  protected
+    FTheLogger: TLazLogger;
+    FOnDbgOutCount, FOnDebugLnCount: Integer;
+    FOnDbgOutText, FOnDebugLnText: string;
+    procedure TestOnDbgOut(Sender: TObject; S: string; var Handled: Boolean);
+    procedure TestOnDebugln(Sender: TObject; S: string; var Handled: Boolean);
+    procedure InitLogger;
+    procedure AssertDbgOut(Name: string; ExpCount: integer; ExpText: String);
+    procedure AssertDebugLn(Name: string; ExpCount: integer; ExpText: String);
+  published
+    procedure TestEvent;
+  end;
+
+implementation
+
+procedure TTestLazLogger.TestOnDbgOut(Sender: TObject; S: string; var Handled: Boolean);
+begin
+  inc(FOnDbgOutCount);
+  FOnDbgOutText := FOnDbgOutText + s;
+  Handled := True;
+end;
+
+procedure TTestLazLogger.TestOnDebugln(Sender: TObject; S: string; var Handled: Boolean);
+begin
+  inc(FOnDebugLnCount);
+  FOnDebugLnText := FOnDebugLnText + s + LineEnding;
+  Handled := True;
+end;
+
+procedure TTestLazLogger.InitLogger;
+begin
+  FreeAndNil(FTheLogger);
+  FTheLogger := TLazLogger.Create;
+  FTheLogger.OnDebugLn  := @TestOnDebugln;
+  FTheLogger.OnDbgOut  := @TestOnDbgOut;
+end;
+
+procedure TTestLazLogger.AssertDbgOut(Name: string; ExpCount: integer; ExpText: String);
+begin
+  AssertEquals(Name + ' DbgOut call count', ExpCount, FOnDbgOutCount);
+  AssertEquals(Name + ' DbgOut text', ExpText, FOnDbgOutText);
+  FOnDbgOutCount := 0;
+  FOnDbgOutText := '';
+end;
+
+procedure TTestLazLogger.AssertDebugLn(Name: string; ExpCount: integer; ExpText: String);
+begin
+  AssertEquals(Name + ' DebugLn call count', ExpCount, FOnDebugLnCount);
+  AssertEquals(Name + ' DebugLn text', ExpText, FOnDebugLnText);
+  FOnDebugLnCount := 0;
+  FOnDebugLnText := '';
+end;
+
+procedure TTestLazLogger.TestEvent;
+begin
+  InitLogger;
+
+  FTheLogger.DebugLn('a');
+  AssertDebugLn('debugln a', 1, 'a'+LineEnding);
+  AssertDbgOut('debugln a', 0, '');
+
+  FTheLogger.DebugLn('b', 'c');
+  AssertDebugLn('debugln b,c', 1, 'bc'+LineEnding);
+  AssertDbgOut('debugln b,c', 0, '');
+
+  FTheLogger.DebugLn(['d', 1]);
+  AssertDebugLn('debugln d,1', 1, 'd1'+LineEnding);
+  AssertDbgOut('debugln d,1', 0, '');
+
+  FTheLogger.DebugLn('e %d', [1]);
+  AssertDebugLn('debugln e,1', 1, 'e 1'+LineEnding);
+  AssertDbgOut('debugln e,1', 0, '');
+
+
+  FTheLogger.DbgOut('a');
+  AssertDbgOut('DbgOut a', 1, 'a');
+  AssertDebugLn('DbgOut a', 0, '');
+
+  FTheLogger.DbgOut('b', 'c');
+  AssertDbgOut('DbgOut b,c', 1, 'bc');
+  AssertDebugLn('DbgOut b,c', 0, '');
+
+  FTheLogger.DbgOut(['d', 1]);
+  AssertDbgOut('DbgOut d,1', 1, 'd1');
+  AssertDebugLn('DbgOut d,1', 0, '');
+
+  FTheLogger.DbgOut('e %d', [1]);
+  AssertDbgOut('DbgOut e,1', 1, 'e 1');
+  AssertDebugLn('DbgOut e,1', 0, '');
+
+  FTheLogger.DebugLnEnter('a');
+  AssertDebugLn('DebugLnEnter() a', 1, 'a'+LineEnding);
+  AssertDbgOut('DebugLnEnter() a', 0, '');
+
+  FTheLogger.DebugLn('in enter');
+  AssertDebugLn('debugln in enter', 1, '  in enter'+LineEnding);
+  AssertDbgOut('debugln in enter', 0, '');
+
+  FTheLogger.DebugLnExit('b');
+  AssertDebugLn('DebugLnExit() b', 1, 'b'+LineEnding);
+  AssertDbgOut('DebugLnExit() b', 0, '');
+
+  FTheLogger.DebugLn('after exit');
+  AssertDebugLn('debugln after exit', 1, 'after exit'+LineEnding);
+  AssertDbgOut('debugln after exit', 0, '');
+
+
+  FreeAndNil(FTheLogger);
+end;
+
+
+initialization
+
+  RegisterTest(TTestLazLogger);
+end.
+