diff --git a/pkgs/tools/text/gnugrep/default.nix b/pkgs/tools/text/gnugrep/default.nix
index 98a737339d27..fde9123adf29 100644
--- a/pkgs/tools/text/gnugrep/default.nix
+++ b/pkgs/tools/text/gnugrep/default.nix
@@ -13,6 +13,8 @@ stdenv.mkDerivation {
   buildInputs = [ pcre ]
     ++ stdenv.lib.optional (libiconv != null) libiconv;
 
+  patches = [ ./test-localeconv.patch ];
+
   NIX_LDFLAGS = stdenv.lib.optionalString (libiconv != null) "-L${libiconv}/lib -liconv";
 
   doCheck = !stdenv.isDarwin;
diff --git a/pkgs/tools/text/gnugrep/test-localeconv.patch b/pkgs/tools/text/gnugrep/test-localeconv.patch
new file mode 100644
index 000000000000..f5efaf222217
--- /dev/null
+++ b/pkgs/tools/text/gnugrep/test-localeconv.patch
@@ -0,0 +1,18 @@
+--- grep-2.14/gnulib-tests/test-localeconv.c.orig	2013-02-15 18:41:50.213433059 +0000
++++ grep-2.14/gnulib-tests/test-localeconv.c	2013-02-15 18:50:33.964751303 +0000
+@@ -37,13 +37,13 @@
+ 
+     ASSERT (STREQ (l->decimal_point, "."));
+     ASSERT (STREQ (l->thousands_sep, ""));
+-#if !defined __FreeBSD__
++#if !(defined __FreeBSD__ || defined __sun)
+     ASSERT (STREQ (l->grouping, ""));
+ #endif
+ 
+     ASSERT (STREQ (l->mon_decimal_point, ""));
+     ASSERT (STREQ (l->mon_thousands_sep, ""));
+-#if !defined __FreeBSD__
++#if !(defined __FreeBSD__ || defined __sun)
+     ASSERT (STREQ (l->mon_grouping, ""));
+ #endif
+     ASSERT (STREQ (l->positive_sign, ""));