diff -up src/sage/groups/perm_gps/permgroup.py.orig src/sage/groups/perm_gps/permgroup.py
--- src/sage/groups/perm_gps/permgroup.py.orig	2014-11-18 15:27:46.545129943 -0200
+++ src/sage/groups/perm_gps/permgroup.py	2014-11-18 15:27:53.760130038 -0200
@@ -180,8 +180,7 @@ def hap_decorator(f):
     """
     @wraps(f)
     def wrapped(self, n, p=0):
-        if not is_package_installed('gap_packages'):
-            raise RuntimeError("You must install the optional gap_packages package.")
+        raise RuntimeError("gap-hap package not available.")
         load_hap()
         from sage.rings.arith import is_prime
         if not (p == 0 or is_prime(p)):
@@ -3979,8 +3978,7 @@ class PermutationGroup_generic(group.Gro
 
         - David Joyner and Graham Ellis
         """
-        if not is_package_installed('gap_packages'):
-            raise RuntimeError("You must install the optional gap_packages package.")
+        raise RuntimeError("gap-hap package not available.")
         load_hap()
         from sage.rings.arith import is_prime
         if not (p == 0 or is_prime(p)):