diff --git a/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/changelog b/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/changelog
index 4a6caa0d..488db07c 100644
--- a/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/changelog
+++ b/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/changelog
@@ -1,3 +1,9 @@
+pilot-link (0.12.5-dfsg-2debian12.0.0+2~a) bookworm; urgency=medium
+
+  * Fix FTBFS due to syntax in configure.ac.
+
+ -- Slávek Banko <slavek.banko@axis.cz>  Wed, 20 Sep 2021 00:48:20 +0200
+
 pilot-link (0.12.5-dfsg-2debian11.0.0+0~a) bullseye; urgency=medium
 
   * Build a package for KPilot needs in Trinity.
diff --git a/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/patches/0002-Fix-configure-syntax.patch b/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/patches/0002-Fix-configure-syntax.patch
new file mode 100644
index 00000000..06ff428f
--- /dev/null
+++ b/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/patches/0002-Fix-configure-syntax.patch
@@ -0,0 +1,22 @@
+Index: b/configure.ac
+===================================================================
+--- a/configure.ac
++++ b/configure.ac
+@@ -392,11 +392,13 @@
+ 		dnl Determine if system popt is good enough
+ 		save_LIBS="$LIBS"
+ 		AC_CHECK_HEADER(popt.h,
+-			AC_CHECK_DECL(POPT_BIT_SET,
+-				AC_CHECK_LIB(popt, poptStrippedArgv,,
+-					[with_included_popt="yes"]),
++			[AC_CHECK_DECL(POPT_BIT_SET,
++				[AC_CHECK_LIB(popt, poptStrippedArgv,,
++					[with_included_popt="yes"]
++				)],
+ 				[with_included_popt="yes"],
+-				[#include <popt.h>]),
++				[#include <popt.h>]
++			)],
+ 			[with_included_popt="yes"]
+ 		)
+ 		LIBS="$save_LIBS"
diff --git a/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/patches/series b/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/patches/series
index 0b81e5bc..dd62b305 100644
--- a/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/patches/series
+++ b/debian/pilot-link/pilot-link-0.12.5-dfsg/debian/patches/series
@@ -5,3 +5,4 @@ colourcorrect
 10_clie_sj22.patch
 31_pilot-addresses.1
 0001-Don-t-use-PERL_POLLUTE-macros.patch
+0002-Fix-configure-syntax.patch