diff -Nru units-2.21/debian/changelog units-2.21/debian/changelog
--- units-2.21/debian/changelog	2020-11-21 14:46:34.000000000 +0000
+++ units-2.21/debian/changelog	2022-01-30 20:16:37.000000000 +0000
@@ -1,3 +1,11 @@
+units (2.21-2) unstable; urgency=medium
+
+  * Apply the patch provided by upstream to fix segfaults when performing
+    verbose inverse lookups of table-driven units. Closes: #1003708.
+  * Standards-Version 4.6.0, no change required.
+
+ -- Stephen Kitt <skitt@debian.org>  Sun, 30 Jan 2022 21:16:37 +0100
+
 units (2.21-1) unstable; urgency=medium
 
   * New upstream release.
diff -Nru units-2.21/debian/control units-2.21/debian/control
--- units-2.21/debian/control	2020-11-21 14:39:47.000000000 +0000
+++ units-2.21/debian/control	2022-01-30 20:15:50.000000000 +0000
@@ -7,7 +7,7 @@
                libreadline-dev,
                python3,
                texinfo
-Standards-Version: 4.5.1
+Standards-Version: 4.6.0
 Vcs-Browser: https://salsa.debian.org/debian/units
 Vcs-Git: https://salsa.debian.org/debian/units.git
 Homepage: https://www.gnu.org/software/units/
diff -Nru units-2.21/debian/patches/inverse-segfault.patch units-2.21/debian/patches/inverse-segfault.patch
--- units-2.21/debian/patches/inverse-segfault.patch	1970-01-01 00:00:00.000000000 +0000
+++ units-2.21/debian/patches/inverse-segfault.patch	2022-01-30 20:11:50.000000000 +0000
@@ -0,0 +1,14 @@
+Description: Avoid segfaulting on inverse table-driven lookups
+Author: Adrian Mariano <radian@cox.net>
+
+--- a/units.c
++++ b/units.c
+@@ -2973,7 +2973,7 @@
+      return 1;
+    }
+    if (flags.verbose==2)
+-     logprintf("\t%s = %s(", havestr, fun->inverse.param);
++     logprintf("\t%s = %s(", havestr, fun->name);
+    else if (flags.verbose==1) 
+      logputchar('\t');
+    showunit(have);
diff -Nru units-2.21/debian/patches/series units-2.21/debian/patches/series
--- units-2.21/debian/patches/series	2017-10-26 09:35:35.000000000 +0000
+++ units-2.21/debian/patches/series	2022-01-29 21:56:38.000000000 +0000
@@ -3,3 +3,4 @@
 no-currency-update.patch
 manpage-typos.patch
 units_cur-python3.patch
+inverse-segfault.patch