diff --git a/components/tachart/test/AssertHelpers.pas b/components/tachart/test/AssertHelpers.pas
index 3bbf488f8f..219d825ab9 100644
--- a/components/tachart/test/AssertHelpers.pas
+++ b/components/tachart/test/AssertHelpers.pas
@@ -15,6 +15,10 @@ type
       const AExpected, AActual: array of Double; ADelta: Double = 0.0); overload;
     class procedure AssertEquals(
       const AExpected, AActual: array of Double; ADelta: Double = 0.0); overload;
+    class procedure AssertEquals(
+      const AMessage: String; const AExpected, AActual: array of Boolean); overload;
+    class procedure AssertEquals(
+      const AExpected, AActual: array of Boolean); overload;
   end;
 
 implementation
@@ -22,13 +26,23 @@ implementation
 uses
   SysUtils;
 
-function DoubleArrayToStr(const AData: array of Double): String;
+function BooleanArrayEqual(const AA, AB: array of Boolean): Boolean;
 var
-  a: Double;
+  len: Integer;
+begin
+  len := Length(AA);
+  if len <> Length(AB) then exit(false);
+  if len = 0 then exit(true);
+  Result := CompareByte(AA[0], AB[0], len) = 0;
+end;
+
+function BooleanArrayToStr(const AData: array of Boolean): String;
+var
+  b: Boolean;
 begin
   Result := '';
-  for a in AData do
-    Result += Format('%g,', [a]);
+  for b in AData do
+    Result += BoolToStr(b, 'true,', 'false,');
   Delete(Result, Length(Result), 1);
 end;
 
@@ -42,14 +56,41 @@ begin
   Result := true;
 end;
 
+function DoubleArrayToStr(const AData: array of Double): String;
+var
+  a: Double;
+begin
+  Result := '';
+  for a in AData do
+    Result += Format('%g,', [a]);
+  Delete(Result, Length(Result), 1);
+end;
+
 { TAssertHelper }
 
+class procedure TAssertHelper.AssertEquals(
+  const AExpected, AActual: array of Boolean);
+begin
+  AssertEquals('', AExpected, AActual);
+end;
+
 class procedure TAssertHelper.AssertEquals(
   const AExpected, AActual: array of Double; ADelta: Double);
 begin
   AssertEquals('', AExpected, AActual, ADelta);
 end;
 
+class procedure TAssertHelper.AssertEquals(
+  const AMessage: String; const AExpected, AActual: array of Boolean);
+var
+  expectedStr, actualStr: String;
+begin
+  if BooleanArrayEqual(AExpected, AActual) then exit;
+  expectedStr := BooleanArrayToStr(AExpected);
+  actualStr := BooleanArrayToStr(AActual);
+  Fail(AMessage + ComparisonMsg(expectedStr, actualStr));
+end;
+
 class procedure TAssertHelper.AssertEquals(
   const AMessage: String; const AExpected, AActual: array of Double;
   ADelta: Double);
@@ -59,8 +100,12 @@ begin
   if DoubleArrayEqual(AExpected, AActual, ADelta) then exit;
   expectedStr := DoubleArrayToStr(AExpected);
   actualStr := DoubleArrayToStr(AActual);
-  Fail(AMessage + Format(SCompare, [expectedStr, actualStr]));
+  Fail(AMessage + ComparisonMsg(expectedStr, actualStr));
 end;
 
+
+initialization
+  Random; // Workaround for issue #21808.
+
 end.
 
diff --git a/components/tachart/test/UtilsTest.pas b/components/tachart/test/UtilsTest.pas
index e3dcac021b..199ce88902 100644
--- a/components/tachart/test/UtilsTest.pas
+++ b/components/tachart/test/UtilsTest.pas
@@ -83,7 +83,7 @@ type
 implementation
 
 uses
-  Math, TAGeometry, TAMath;
+  Math, TAGeometry, TAMath, AssertHelpers;
 
 { TIntervalListTest }
 
@@ -407,30 +407,9 @@ end;
 
 procedure TPublishedIntegerSetTest.TestAsBooleans;
 
-  function BooleansToStr(const A: array of Boolean): String;
-  var
-    b: Boolean;
-  begin
-    Result := '';
-    for b in A do begin
-      if Result <> '' then
-        Result += ',';
-      Result += BoolToStr(b, 'true', 'false');
-    end;
-    Result := '[' + Result + ']';
-  end;
-
   procedure AssertBooleans(const AExpected: array of Boolean; ACount: Integer);
-  var
-    actual: array of Boolean;
-    len: Integer;
   begin
-    actual := FISet.AsBooleans(ACount);
-    len := Length(actual);
-    AssertTrue(
-      BooleansToStr(actual) + ' = ' + BooleansToStr(AExpected),
-      (len = Length(AExpected)) and
-      ((len = 0) or (CompareByte(actual[0], AExpected[0], len) = 0)));
+    AssertEquals(AExpected, FISet.AsBooleans(ACount));
   end;
 
 begin