diff --git a/.gitignore b/.gitignore
index d8339fa..f7b8ee0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -56,3 +56,5 @@ SWI-Prolog-5.7.11.pdf
 /SWI-Prolog-7.6.0.pdf
 /swipl-7.6.1_repackaged.tar.gz
 /SWI-Prolog-7.6.1.pdf
+/SWI-Prolog-7.6.4.pdf
+/swipl-7.6.4_repackaged.tar.gz
diff --git a/pl.spec b/pl.spec
index 84badd7..ab6c828 100644
--- a/pl.spec
+++ b/pl.spec
@@ -2,7 +2,7 @@
 %global separate_xpce 1
 
 Name:       pl
-Version:    7.6.1
+Version:    7.6.4
 Release:    1%{?dist}
 Summary:    SWI-Prolog - Edinburgh compatible Prolog compiler
 Group:      Development/Languages
@@ -413,6 +413,9 @@ find packages/jpl/examples -name ".cvsignore" | xargs rm -f
 
 
 %changelog
+* Mon Jan 15 2018 Petr Pisar <ppisar@redhat.com> - 7.6.4-1
+- 7.6.4 bump
+
 * Wed Nov 08 2017 Petr Pisar <ppisar@redhat.com> - 7.6.1-1
 - 7.6.1 bump
 - License changed from ((BSD and (GPLv2+ with exceptions or Artistic 2.0)) and
diff --git a/sources b/sources
index e5cd134..2baeb37 100644
--- a/sources
+++ b/sources
@@ -1,3 +1,3 @@
 SHA512 (userguide.html.tgz) = baa16d8f06a666e77ef45aaf7708e877710bfcb8fc0fb519bc70c54619c45def2d2ab4feaa0f1a1875b2a2270e8907551b63582da1b4beaa5b50f013a41d7ab9
-SHA512 (swipl-7.6.1_repackaged.tar.gz) = 245900fdd148ac5c434bb6e8f546cf14ec449ac9b2807b4f4e7761a7c612c2307cb2242425637a73dd88918717371b1423fad5e71eff437ed136743bba6a73b4
-SHA512 (SWI-Prolog-7.6.1.pdf) = 98179a3325a83beb32f46cd8643b124d6de74908e03aef323a23572e99203b2d766f4c56721a40013b9dbf5f97e72610776f966adb128c0e11861b3c668d1b9a
+SHA512 (swipl-7.6.4_repackaged.tar.gz) = 98631ac6f2be8834cd24a0617cd03d9fcdf65d22411c823e0c7017abec5233c269441cb055fa126e0a67d0e3d5d4a0c3562fa23cc89129d36ee98f9f99bba022
+SHA512 (SWI-Prolog-7.6.4.pdf) = 027099fcf05d9f60c47e6ecf6e73d902416d5c97566f922da4edf013a2da8d138505ec10913e2f7188c8446c913a2a58b6f21d5c72ac7ab09e6c37ac40ac9837
diff --git a/tests/c_binding/calc.c b/tests/c_binding/calc.c
index 27390b9..dca0a35 100644
--- a/tests/c_binding/calc.c
+++ b/tests/c_binding/calc.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <string.h>
 #include <SWI-Prolog.h>
 
 #define MAXLINE 1024