diff --git a/components/tachart/tacustomsource.pas b/components/tachart/tacustomsource.pas
index 6de4ecd8ca..5de0f02505 100644
--- a/components/tachart/tacustomsource.pas
+++ b/components/tachart/tacustomsource.pas
@@ -785,25 +785,29 @@ begin
   if FExtentIsValid then exit(FExtent);
   FExtent := EmptyExtent;
 
-  if HasXErrorBars then
-    for i := 0 to Count - 1 do begin
-      GetXErrorBarLimits(i, vhi, vlo);
-      UpdateMinMax(vhi, FExtent.a.X, FExtent.b.X);
-      UpdateMinMax(vlo, FExtent.a.X, FExtent.b.X);
-    end
-  else
-    for i:=0 to Count - 1 do
-      UpdateMinMax(Item[i]^.X, FExtent.a.X, FExtent.b.X);
+  if XCount > 0 then begin
+    if HasXErrorBars then
+      for i := 0 to Count - 1 do begin
+        GetXErrorBarLimits(i, vhi, vlo);
+        UpdateMinMax(vhi, FExtent.a.X, FExtent.b.X);
+        UpdateMinMax(vlo, FExtent.a.X, FExtent.b.X);
+      end
+    else
+      for i:=0 to Count - 1 do
+        UpdateMinMax(Item[i]^.X, FExtent.a.X, FExtent.b.X);
+  end;
 
-  if HasYErrorBars then
-    for i := 0 to Count - 1 do begin
-      GetYErrorBarLimits(i, vhi, vlo);
-      UpdateMinMax(vhi, FExtent.a.Y, FExtent.b.Y);
-      UpdateMinMax(vlo, FExtent.a.Y, FExtent.b.Y);
-    end
-  else
-    for i:=0 to Count - 1 do
-      UpdateMinMax(Item[i]^.Y, FExtent.a.Y, FExtent.b.Y);
+  if YCount > 0 then begin
+    if HasYErrorBars then
+      for i := 0 to Count - 1 do begin
+        GetYErrorBarLimits(i, vhi, vlo);
+        UpdateMinMax(vhi, FExtent.a.Y, FExtent.b.Y);
+        UpdateMinMax(vlo, FExtent.a.Y, FExtent.b.Y);
+      end
+    else
+      for i:=0 to Count - 1 do
+        UpdateMinMax(Item[i]^.Y, FExtent.a.Y, FExtent.b.Y);
+  end;
 
   FExtentIsValid := true;
   Result := FExtent;
diff --git a/components/tachart/tasources.pas b/components/tachart/tasources.pas
index 5c038f2b7f..f036d8db8c 100644
--- a/components/tachart/tasources.pas
+++ b/components/tachart/tasources.pas
@@ -870,8 +870,8 @@ end;
 procedure TListChartSource.UpdateCachesAfterAdd(AX, AY: Double);
 begin
   if FExtentIsValid then begin
-    UpdateMinMax(AX, FExtent.a.X, FExtent.b.X);
-    UpdateMinMax(AY, FExtent.a.Y, FExtent.b.Y);
+    if FXCount > 0 then UpdateMinMax(AX, FExtent.a.X, FExtent.b.X);
+    if FYCount > 0 then UpdateMinMax(AY, FExtent.a.Y, FExtent.b.Y);
   end;
   if FValuesTotalIsValid then
     FValuesTotal += NumberOr(AY);