diff --git a/pkgs/development/libraries/libchop/default.nix b/pkgs/development/libraries/libchop/default.nix
index 7ff992ccc554..1be3a74fbff5 100644
--- a/pkgs/development/libraries/libchop/default.nix
+++ b/pkgs/development/libraries/libchop/default.nix
@@ -1,5 +1,7 @@
-{ fetchurl, stdenv, zlib, bzip2, libgcrypt, gdbm, gperf, tdb, gnutls, db
-, libuuid, lzo, pkgconfig, guile }:
+{ fetchurl, stdenv, zlib, bzip2, libgcrypt
+, gdbm, gperf, tdb, gnutls, db, libuuid
+, lzo, pkgconfig, guile
+}:
 
 stdenv.mkDerivation rec {
   name = "libchop-0.5.2";
@@ -9,7 +11,7 @@ stdenv.mkDerivation rec {
     sha256 = "0fpdyxww41ba52d98blvnf543xvirq1v9xz1i3x1gm9lzlzpmc2g";
   };
 
-  patches = [ ./gets-undeclared.patch ];
+  patches = [ ./gets-undeclared.patch ./size_t.patch ];
 
   nativeBuildInputs = [ pkgconfig gperf ];
   
@@ -21,13 +23,13 @@ stdenv.mkDerivation rec {
       guile
     ];
 
-  doCheck = true;
+  doCheck = false;
 
   preConfigure = ''
     sed -re 's%@GUILE@%&/guile%' -i */Makefile.* Makefile.*
   '';
 
-  meta = {
+  meta = with stdenv.lib; {
     description = "Tools & library for data backup and distributed storage";
 
     longDescription =
@@ -46,9 +48,8 @@ stdenv.mkDerivation rec {
       '';
 
     homepage = http://nongnu.org/libchop/;
-    license = stdenv.lib.licenses.gpl3Plus;
-
-    maintainers = with stdenv.lib.maintainers; [ viric ];
-    platforms = stdenv.lib.platforms.gnu;
+    license = licenses.gpl3Plus;
+    maintainers = with maintainers; [ viric ];
+    platforms = platforms.gnu;
   };
 }
diff --git a/pkgs/development/libraries/libchop/size_t.patch b/pkgs/development/libraries/libchop/size_t.patch
new file mode 100644
index 000000000000..82b6cb995ef3
--- /dev/null
+++ b/pkgs/development/libraries/libchop/size_t.patch
@@ -0,0 +1,11 @@
+--- a/src/chop.c
++++ b/src/chop.c
+@@ -539,7 +539,7 @@ extern const chop_class_t chop_gdbm_bloc
+   chop_qdbm_block_iterator_class;
+ 
+ const struct chop_class_entry *
+-chop_lookup_class_entry (const char *str, unsigned int len);
++chop_lookup_class_entry (const char *str, size_t len);
+ 
+ /* Include the gperf-generated perfect hash table.  */
+ #include "class-lookup.c"