diff --git a/pkgs/development/r-modules/patches/rhdf5.patch b/pkgs/development/r-modules/patches/rhdf5.patch
index eb2f28d01876..129a8a225f0d 100644
--- a/pkgs/development/r-modules/patches/rhdf5.patch
+++ b/pkgs/development/r-modules/patches/rhdf5.patch
@@ -35,11 +35,12 @@ index b326444..5d58b4a 100644
    /* return value of lock attempt */
    PROTECT(Rval = allocVector(INTSXP, 1));
 diff --git a/src/h5testLock.h b/src/h5testLock.h
-index 2c1c5e4..660c747 100644
+index 2c1c5e4..25914ff 100644
 --- a/src/h5testLock.h
 +++ b/src/h5testLock.h
-@@ -1,5 +1,4 @@
+@@ -1,5 +1,5 @@
  #include <fcntl.h>
++#include <unistd.h>
  #include "myhdf5.h"
 -#include <H5private.h>