diff --git a/pkgs/development/tools/misc/gnum4/default.nix b/pkgs/development/tools/misc/gnum4/default.nix
index 8d3d175e730..1f026f12f52 100644
--- a/pkgs/development/tools/misc/gnum4/default.nix
+++ b/pkgs/development/tools/misc/gnum4/default.nix
@@ -9,7 +9,8 @@ stdenv.mkDerivation {
   };
 
   doCheck = !stdenv.isDarwin
-    && !stdenv.isCygwin;                   # XXX: `test-dup2' fails on Cygwin
+    && !stdenv.isCygwin                    # XXX: `test-dup2' fails on Cygwin
+    && !stdenv.isSunOS;                    # XXX: `test-setlocale2.sh' fails
 
   # Upstream is aware of it; it may be in the next release.
   patches = [ ./s_isdir.patch ./readlink-EINVAL.patch ];