diff --git a/components/fpspreadsheet/tests/datetests.pas b/components/fpspreadsheet/tests/datetests.pas
index 1c03b0694..b6df89416 100644
--- a/components/fpspreadsheet/tests/datetests.pas
+++ b/components/fpspreadsheet/tests/datetests.pas
@@ -372,7 +372,8 @@ var
   ActualDateTime: TDateTime;
   ErrorMargin: TDateTime; //margin for error in comparison test
 begin
-  ErrorMargin:=0.000000000000001;
+  //ErrorMargin:=0.000000000000001;     // = 1E-15 = 9E-11 sec
+  ErrorMargin := 1E-5/(24*60*60*1000);  // = 10 nsec = 1E-8 sec   // 1 ns fails
   if Row>High(SollDates) then
     fail('Error in test code: array bounds overflow. Check array size is correct.');
 
diff --git a/components/fpspreadsheet/tests/spreadtestgui.lpi b/components/fpspreadsheet/tests/spreadtestgui.lpi
index cbbbad4a0..5fca12336 100644
--- a/components/fpspreadsheet/tests/spreadtestgui.lpi
+++ b/components/fpspreadsheet/tests/spreadtestgui.lpi
@@ -80,6 +80,7 @@
       <Unit1>
         <Filename Value="datetests.pas"/>
         <IsPartOfProject Value="True"/>
+        <UnitName Value="datetests"/>
       </Unit1>
       <Unit2>
         <Filename Value="stringtests.pas"/>