diff --git a/debian/patches/debian/0002-pthread.patch b/debian/patches/debian/0002-pthread.patch
new file mode 100644
index 0000000..ea5f32e
--- /dev/null
+++ b/debian/patches/debian/0002-pthread.patch
@@ -0,0 +1,15 @@
+Author: Daniel Baumann <daniel@debian.org>
+Description: Fixing FTBFS about undeclared PTHREAD_MUTEX_INITIALIZER by including missing pthread header.
+
+diff -Naurp tarlz.orig/extended.cc tarlz/extended.cc
+--- tarlz.orig/extended.cc
++++ tarlz/extended.cc
+@@ -21,6 +21,8 @@
+ #include <cerrno>
+ #include <cstdio>
+ 
++#include <pthread.h>
++
+ #include "tarlz.h"
+ #include "common_mutex.h"
+ 
diff --git a/debian/patches/series b/debian/patches/series
index 655df63..abf2679 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -1 +1,2 @@
 debian/0001-build.patch
+debian/0002-pthread.patch