diff --git a/.gitattributes b/.gitattributes
index 49fa6ad11e..59a0844036 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -12427,6 +12427,7 @@ tests/webtbs/tw12993.pp svneol=native#text/plain
 tests/webtbs/tw13015.pp svneol=native#text/plain
 tests/webtbs/tw13019.pp svneol=native#text/plain
 tests/webtbs/tw13075.pp svneol=native#text/plain
+tests/webtbs/tw13076.pp svneol=native#text/plain
 tests/webtbs/tw1310.pp svneol=native#text/plain
 tests/webtbs/tw13110.pp svneol=native#text/plain
 tests/webtbs/tw13133.pp svneol=native#text/plain
diff --git a/rtl/objpas/sysutils/sysstr.inc b/rtl/objpas/sysutils/sysstr.inc
index bc930c75e3..16336ac961 100644
--- a/rtl/objpas/sysutils/sysstr.inc
+++ b/rtl/objpas/sysutils/sysstr.inc
@@ -2277,7 +2277,7 @@ Var
                     end;
                   If thousand And (Digits[N]<>'-') Then
                     Begin
-                    If (DigitExponent Mod 3 = 0) And (DigitExponent>0) Then
+                    If (DigitExponent Mod 3 = 0) And (DigitExponent>0) and (N > 1) Then
                       Begin
                       Buf[0] := FormatSettings.ThousandSeparator;
                       Inc(Buf);
diff --git a/tests/webtbs/tw13076.pp b/tests/webtbs/tw13076.pp
new file mode 100644
index 0000000000..6ea5c8bbcd
--- /dev/null
+++ b/tests/webtbs/tw13076.pp
@@ -0,0 +1,28 @@
+{$ifdef fpc}
+{$mode objfpc}
+{$endif}
+program tw12385;
+
+uses
+  SysUtils;
+
+var
+  s: string;
+  cr: Extended;
+
+Procedure TestIt(CR : Extended; Fmt,Expected : String);
+
+begin
+  S:=FormatFloat(Fmt,cr);
+  If S<>Expected then
+    begin
+    Writeln('"',S,'"<>"',Expected,'" (latter is correct)');
+    Halt(1);
+    end;
+end;
+
+begin
+  DecimalSeparator:='.';
+  ThousandSeparator:=',';
+  TestIt(-10,'###,###,##0.00','-10.00');
+end.