diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/changelog vtk9-9.1.0+really9.1.0+dfsg2/debian/changelog
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/changelog	2023-08-22 10:27:20.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/changelog	2024-02-27 10:02:25.000000000 +1300
@@ -1,3 +1,10 @@
+vtk9 (9.1.0+really9.1.0+dfsg2-7.1) UNRELEASED; urgency=medium
+
+  * Non-maintainer upload.
+  * Rename libraries for 64-bit time_t transition.
+
+ -- Michael Hudson-Doyle <michael.hudson@ubuntu.com>  Tue, 27 Feb 2024 10:02:25 +1300
+
 vtk9 (9.1.0+really9.1.0+dfsg2-7) unstable; urgency=medium
 
   * Team upload.
diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/control vtk9-9.1.0+really9.1.0+dfsg2/debian/control
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/control	2023-08-22 07:01:21.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/control	2024-02-27 10:02:25.000000000 +1300
@@ -117,7 +117,7 @@
          libtheora-dev,
          libtiff-dev,
          libutfcpp-dev,
-         libvtk9.1 (= ${binary:Version}),
+         libvtk9.1t64 (= ${binary:Version}),
          libvtk9-java (= ${binary:Version}) [!hppa !hurd-any !kfreebsd-any],
          libx11-dev,
          libxft-dev,
@@ -140,12 +140,13 @@
  This package provides the VTK header files required to compile
  C++ programs that use VTK to do 3D visualisation.
 
-Package: libvtk9.1
+Package: libvtk9.1t64
+Provides: ${t64:Provides}
 Architecture: any
 Multi-Arch: same
 Section: libs
-Breaks: libvtk9 (<< 9.1.0+really9.1.0)
-Replaces: libvtk9 (<< 9.1.0+really9.1.0)
+Breaks: libvtk9.1 (<< ${source:Version}), libvtk9 (<< 9.1.0+really9.1.0)
+Replaces: libvtk9.1, libvtk9 (<< 9.1.0+really9.1.0)
 Depends: ${misc:Depends},
          ${shlibs:Depends}
 Suggests: mpi-default-bin,
@@ -179,7 +180,7 @@
 Package: python3-vtk9
 Architecture: any
 Section: python
-Depends: libvtk9.1 (= ${binary:Version}),
+Depends: libvtk9.1t64 (= ${binary:Version}),
          python3-mpi4py,
          ${misc:Depends},
          ${python3:Depends},
@@ -200,7 +201,7 @@
 Package: vtk9
 Architecture: any
 Section: interpreters
-Depends: libvtk9.1 (= ${binary:Version}),
+Depends: libvtk9.1t64 (= ${binary:Version}),
          ${misc:Depends},
          ${shlibs:Depends}
 Suggests: vtk9-doc,
@@ -240,7 +241,11 @@
  .
  This package provides examples for VTK9
 
-Package: libvtk9.1-qt
+Package: libvtk9.1t64-qt
+Provides: ${t64:Provides}
+X-Time64-Compat: libvtk9.1-qt
+Replaces: libvtk9.1-qt
+Breaks: libvtk9.1-qt (<< ${source:Version})
 Architecture: any
 Multi-Arch: same
 Section: libs
@@ -258,7 +263,7 @@
 Multi-Arch: same
 Section: libdevel
 Depends: libvtk9-dev (= ${binary:Version}),
-         libvtk9.1-qt (= ${binary:Version}),
+         libvtk9.1t64-qt (= ${binary:Version}),
          ${misc:Depends},
          ${shlibs:Depends},
          qtbase5-dev,
diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1.install vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1.install
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1.install	2023-08-22 07:01:21.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1.install	1970-01-01 12:00:00.000000000 +1200
@@ -1,2 +0,0 @@
-usr/lib/*/*.so.*
-usr/lib/*/vtk
diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1.lintian-overrides vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1.lintian-overrides
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1.lintian-overrides	2023-08-22 07:01:21.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1.lintian-overrides	1970-01-01 12:00:00.000000000 +1200
@@ -1 +0,0 @@
-libvtk9.1: package-name-doesnt-match-sonames
diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1-qt.install vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1-qt.install
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1-qt.install	2023-08-22 07:01:21.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1-qt.install	1970-01-01 12:00:00.000000000 +1200
@@ -1 +0,0 @@
-usr/lib/*/*Qt*.so.*
diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1-qt.lintian-overrides vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1-qt.lintian-overrides
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1-qt.lintian-overrides	2023-08-22 07:01:21.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1-qt.lintian-overrides	1970-01-01 12:00:00.000000000 +1200
@@ -1 +0,0 @@
-libvtk9.1-qt: package-name-doesnt-match-sonames
diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64.install vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64.install
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64.install	1970-01-01 12:00:00.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64.install	2024-02-27 10:02:25.000000000 +1300
@@ -0,0 +1,2 @@
+usr/lib/*/*.so.*
+usr/lib/*/vtk
diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64.lintian-overrides vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64.lintian-overrides
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64.lintian-overrides	1970-01-01 12:00:00.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64.lintian-overrides	2024-02-27 10:02:25.000000000 +1300
@@ -0,0 +1,2 @@
+libvtk9.1t64: package-name-doesnt-match-sonames
+libvtk9.1t64: package-name-doesnt-match-sonames libvtk9.1
diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64-qt.install vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64-qt.install
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64-qt.install	1970-01-01 12:00:00.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64-qt.install	2024-02-27 10:02:25.000000000 +1300
@@ -0,0 +1 @@
+usr/lib/*/*Qt*.so.*
diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64-qt.lintian-overrides vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64-qt.lintian-overrides
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64-qt.lintian-overrides	1970-01-01 12:00:00.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/libvtk9.1t64-qt.lintian-overrides	2024-02-27 10:02:25.000000000 +1300
@@ -0,0 +1,2 @@
+libvtk9.1t64-qt: package-name-doesnt-match-sonames
+libvtk9.1t64-qt: package-name-doesnt-match-sonames libvtk9.1-qt
diff -Nru vtk9-9.1.0+really9.1.0+dfsg2/debian/rules vtk9-9.1.0+really9.1.0+dfsg2/debian/rules
--- vtk9-9.1.0+really9.1.0+dfsg2/debian/rules	2023-08-22 07:01:21.000000000 +1200
+++ vtk9-9.1.0+really9.1.0+dfsg2/debian/rules	2024-02-27 10:02:25.000000000 +1300
@@ -105,7 +105,7 @@
 	find $(CURDIR)/debian/libvtk9-dev/ -name "*Qt*" -exec rm {} \; || true
 	find $(CURDIR)/debian/libvtk9-dev/ -name "libvtkRenderingPythonTkWidgets.so" -exec rm {} \; || true
 	find $(CURDIR)/debian/libvtk9-dev/usr/include/ -name "Q*" -exec rm {} \; || true
-	find $(CURDIR)/debian/libvtk9.1/ -name "*Qt*" -exec rm {} \; || true
+	find $(CURDIR)/debian/libvtk9.1t64/ -name "*Qt*" -exec rm {} \; || true
 	find $(CURDIR)/debian/tmp/usr/share/doc/vtk-9.0/doxygen -name "_formulas.log" -exec rm {} \; || true
 	find $(CURDIR)/debian/build/Utilities/Doxygen/doc/html -name "_formulas.log" -exec rm {} \; || true