diff --git a/random/bernoulli.lisp b/random/bernoulli.lisp
index 34d51fbbc881cf5f6811a312ab6d708c66fdd85d..9a4ee67ba97e2bdb54757494911ee37ed94c7710 100644
--- a/random/bernoulli.lisp
+++ b/random/bernoulli.lisp
@@ -1,14 +1,15 @@
 ;; Bernoulli distribution
 ;; Liam Healy, Sat Nov 25 2006 - 16:59
-;; Time-stamp: <2009-05-24 22:16:20EDT bernoulli.lisp>
+;; Time-stamp: <2009-05-26 22:56:49EDT bernoulli.lisp>
 ;; $Id$
 
 (in-package :gsl)
 
 (defmfun sample
-    ((generator random-number-generator) (type (eql 'bernoulli)) &key p)
+    ((generator random-number-generator) (type (eql 'bernoulli))
+     &key probability)
   "gsl_ran_bernoulli"
-  (((mpointer generator) :pointer) (p :double))
+  (((mpointer generator) :pointer) (probability :double))
   :definition :method
   :c-return :uint
   :documentation			; FDL
@@ -31,5 +32,5 @@
   (let ((rng (make-random-number-generator +mt19937+ 0)))
      (loop for i from 0 to 10
 	   collect
-	   (sample rng 'bernoulli :p 0.5d0)))
+	   (sample rng 'bernoulli :probability 0.5d0)))
   (bernoulli-pdf 0 0.5d0))
diff --git a/tests/bernoulli.lisp b/tests/bernoulli.lisp
index 3be67a655e44b3192f84ee522abab1a7373a32a4..97f26b044f35e59c9a5e655d1ab170c87e066e6d 100644
--- a/tests/bernoulli.lisp
+++ b/tests/bernoulli.lisp
@@ -8,7 +8,7 @@
    (MULTIPLE-VALUE-LIST
     (LET ((RNG (MAKE-RANDOM-NUMBER-GENERATOR +MT19937+ 0)))
       (LOOP FOR I FROM 0 TO 10 COLLECT
-	   (sample rng 'bernoulli :p 0.5d0)))))
+	   (sample rng 'bernoulli :probability 0.5d0)))))
   (LISP-UNIT::ASSERT-NUMERICAL-EQUAL
    (LIST 0.5d0)
    (MULTIPLE-VALUE-LIST (BERNOULLI-PDF 0 0.5d0))))