diff -Nru tkgate-2.1+repack/debian/changelog tkgate-2.1+repack/debian/changelog
--- tkgate-2.1+repack/debian/changelog	2019-01-14 16:29:11.000000000 +0000
+++ tkgate-2.1+repack/debian/changelog	2020-08-21 17:33:38.000000000 +0000
@@ -1,3 +1,10 @@
+tkgate (2.1+repack-4) unstable; urgency=medium
+
+  * applied sei-lisa's patch, thanks! Closes:  #968605
+  * updated Standards-Version: 4.5.0, debhelper-compat = 12
+
+ -- Georges Khaznadar <georgesk@debian.org>  Fri, 21 Aug 2020 19:33:38 +0200
+
 tkgate (2.1+repack-3) unstable; urgency=medium
 
   * modified the installation file for of tkgate-doc, thanks to
diff -Nru tkgate-2.1+repack/debian/compat tkgate-2.1+repack/debian/compat
--- tkgate-2.1+repack/debian/compat	2019-01-06 18:02:00.000000000 +0000
+++ tkgate-2.1+repack/debian/compat	1970-01-01 00:00:00.000000000 +0000
@@ -1 +0,0 @@
-11
diff -Nru tkgate-2.1+repack/debian/control tkgate-2.1+repack/debian/control
--- tkgate-2.1+repack/debian/control	2019-01-06 18:02:00.000000000 +0000
+++ tkgate-2.1+repack/debian/control	2020-08-21 17:33:38.000000000 +0000
@@ -4,9 +4,16 @@
 Maintainer: Debian Science Maintainers <debian-science-maintainers@lists.alioth.debian.org>
 Uploaders: أحمد المحمودي (Ahmed El-Mahmoudy) <aelmahmoudy@sabily.org>,
  Georges Khaznadar <georgesk@debian.org>
-Standards-Version: 4.3.0
-Build-Depends: debhelper (>=11), tcl-dev, tk-dev, bison|byacc, flex,
- xutils-dev, libx11-dev, autotools-dev, libpango1.0-dev
+Standards-Version: 4.5.0
+Build-Depends: debhelper-compat (=12),
+ tcl-dev,
+ tk-dev,
+ bison|byacc,
+ flex,
+ xutils-dev,
+ libx11-dev,
+ autotools-dev,
+ libpango1.0-dev
 Homepage: http://www.tkgate.org/
 Vcs-Browser: https://salsa.debian.org/science-team/tkgate.git
 Vcs-Git: https://salsa.debian.org/science-team/tkgate.git
diff -Nru tkgate-2.1+repack/debian/patches/inverting.patch tkgate-2.1+repack/debian/patches/inverting.patch
--- tkgate-2.1+repack/debian/patches/inverting.patch	1970-01-01 00:00:00.000000000 +0000
+++ tkgate-2.1+repack/debian/patches/inverting.patch	2020-08-21 17:32:34.000000000 +0000
@@ -0,0 +1,13 @@
+Index: tkgate/src/tkgate/and.c
+===================================================================
+--- tkgate.orig/src/tkgate/and.c
++++ tkgate/src/tkgate/and.c
+@@ -328,7 +328,7 @@ int AOX_GateParmList(FILE *f,GCElement *
+       first_pin = 0;
+ 
+       if (gi->Pad[i].iotype == IN && w->invert)
+-	inv = "!";
++	inv = "~";
+ 
+       if (gi->Pad[i].CanAdd)
+ 	fprintf(f,".%s%d",gi->Pad[i].name,j);
diff -Nru tkgate-2.1+repack/debian/patches/series tkgate-2.1+repack/debian/patches/series
--- tkgate-2.1+repack/debian/patches/series	2019-01-06 18:02:00.000000000 +0000
+++ tkgate-2.1+repack/debian/patches/series	2020-08-21 17:31:33.000000000 +0000
@@ -2,3 +2,4 @@
 reproduible-build.patch
 obsolete-Tcl_Interp-result.patch
 acinclude.m4.patch
+inverting.patch