diff -Nru clamfs-1.2.0/debian/changelog clamfs-1.2.0/debian/changelog
--- clamfs-1.2.0/debian/changelog	2020-05-05 21:07:05.000000000 +0000
+++ clamfs-1.2.0/debian/changelog	2021-04-23 13:57:33.000000000 +0000
@@ -1,3 +1,10 @@
+clamfs (1.2.0-2ubuntu1) devel; urgency=medium
+
+  * Fix FTBFS with glibc 2.33:
+    mallinfo() has been deprecated in favor of mallinfo2()
+
+ -- Lukas Märdian <slyon@ubuntu.com>  Fri, 23 Apr 2021 15:57:33 +0200
+
 clamfs (1.2.0-2build2) groovy; urgency=medium
 
   * No-change rebuild against libpocofoundation70
diff -Nru clamfs-1.2.0/debian/patches/glibc-mallinfo2.patch clamfs-1.2.0/debian/patches/glibc-mallinfo2.patch
--- clamfs-1.2.0/debian/patches/glibc-mallinfo2.patch	1970-01-01 00:00:00.000000000 +0000
+++ clamfs-1.2.0/debian/patches/glibc-mallinfo2.patch	2021-04-23 13:56:43.000000000 +0000
@@ -0,0 +1,54 @@
+Description: Make use of mallinfo2, available since glibc-2.33
+ The upgrade to glibc 2.33 deprecated the mallinfo() call in favor of the new
+ mallinfo2() call. Make use of it.
+Author: Lukas Märdian <slyon@ubuntu.com>
+Forwarded: https://github.com/burghardt/clamfs/pull/64
+Last-Update: 2021-04-23
+
+---
+--- clamfs-1.2.0.orig/config.h.in
++++ clamfs-1.2.0/config.h.in
+@@ -56,6 +56,9 @@
+ /* Define to 1 if you have the `mallinfo' function. */
+ #undef HAVE_MALLINFO
+ 
++/* Define to 1 if you have the `mallinfo2' function. */
++#undef HAVE_MALLINFO2
++
+ /* Define to 1 if you have the <malloc.h> header file. */
+ #undef HAVE_MALLOC_H
+ 
+--- clamfs-1.2.0.orig/configure.ac
++++ clamfs-1.2.0/configure.ac
+@@ -31,7 +31,7 @@ AC_FUNC_CLOSEDIR_VOID
+ AC_FUNC_LSTAT
+ AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK
+ AC_FUNC_UTIME_NULL
+-AC_CHECK_FUNCS([fchdir fdatasync fork ftruncate fstatat utimensat posix_fallocate copy_file_range lchown memset mkdir mkfifo rmdir setxattr strdup strerror utime mallinfo])
++AC_CHECK_FUNCS([fchdir fdatasync fork ftruncate fstatat utimensat posix_fallocate copy_file_range lchown memset mkdir mkfifo rmdir setxattr strdup strerror utime mallinfo mallinfo2])
+ 
+ # Check for BSD 4.4 / RFC2292 style fd passing
+ AC_C_FDPASSING
+--- clamfs-1.2.0.orig/src/stats.cxx
++++ clamfs-1.2.0/src/stats.cxx
+@@ -69,7 +69,19 @@ void Stats::dumpFilesystemStatsToLog() {
+ 
+ void Stats::dumpMemoryStatsToLog() {
+     rLog(Info, "--- begin of memory statistics ---");
+-#ifdef HAVE_MALLINFO
++#if defined(HAVE_MALLINFO2)
++    struct mallinfo2 mi = mallinfo2();
++    rLog(Info, "Non-mmapped space allocated (arena):         %zd", mi.arena);
++    rLog(Info, "Number of free chunks (ordblks):             %zd", mi.ordblks);
++    rLog(Info, "Number of free fastbin blocks (smblks):      %zd", mi.smblks);
++    rLog(Info, "Number of mmapped regions (hblks):           %zd", mi.hblks);
++    rLog(Info, "Space allocated in mmapped regions (hblkhd): %zd", mi.hblkhd);
++    rLog(Info, "Maximum total allocated space (usmblks):     %zd", mi.usmblks);
++    rLog(Info, "Space in freed fastbin blocks (fsmblks):     %zd", mi.fsmblks);
++    rLog(Info, "Total allocated space (uordblks):            %zd", mi.uordblks);
++    rLog(Info, "Total free space (fordblks):                 %zd", mi.fordblks);
++    rLog(Info, "Top-most, releasable space (keepcost):       %zd", mi.keepcost);
++#elif defined(HAVE_MALLINFO)
+     struct mallinfo mi = mallinfo();
+     rLog(Info, "Non-mmapped space allocated (arena):         %d", mi.arena);
+     rLog(Info, "Number of free chunks (ordblks):             %d", mi.ordblks);
diff -Nru clamfs-1.2.0/debian/patches/series clamfs-1.2.0/debian/patches/series
--- clamfs-1.2.0/debian/patches/series	2020-01-09 23:59:11.000000000 +0000
+++ clamfs-1.2.0/debian/patches/series	2021-04-23 10:12:56.000000000 +0000
@@ -1 +1,2 @@
 Remove-_start-symbol-check-for-CXX-libraries.patch
+glibc-mallinfo2.patch