diff --git a/src/Makevars b/src/Makevars
index 713b44c..704ac17 100644
--- a/src/Makevars
+++ b/src/Makevars
@@ -1,5 +1,5 @@
 RHDF5_LIBS = $(shell "$(R_HOME)/bin${R_ARCH_BIN}/Rscript" -e 'Rhdf5lib::pkgconfig("PKG_C_LIBS")')
-PKG_LIBS = $(RHDF5_LIBS)
+PKG_LIBS = $(RHDF5_LIBS) -lhdf5
 
 #PKG_CFLAGS = -Wall
 
diff --git a/src/h5testLock.c b/src/h5testLock.c
index b326444..5d58b4a 100644
--- a/src/h5testLock.c
+++ b/src/h5testLock.c
@@ -8,16 +8,16 @@ SEXP _h5fileLock(SEXP _file_name) {
   int lk = -1;
 
   /* create the temporary file */
-  fd = HDopen(file_name, O_RDWR | O_CREAT | O_TRUNC, 0666);
+  fd = open(file_name, O_RDWR | O_CREAT | O_TRUNC, 0666);
 
   /* try to lock file */
-  lk = HDflock(fd, LOCK_EX | LOCK_NB);
+  lk = flock(fd, LOCK_EX | LOCK_NB);
   
   /* unlock so we can remove */
-  HDflock(fd, LOCK_UN);
+  flock(fd, LOCK_UN);
   
   /* close */
-  HDclose(fd);
+  close(fd);
   
   /* return value of lock attempt */
   PROTECT(Rval = allocVector(INTSXP, 1));
diff --git a/src/h5testLock.h b/src/h5testLock.h
index 2c1c5e4..25914ff 100644
--- a/src/h5testLock.h
+++ b/src/h5testLock.h
@@ -1,5 +1,5 @@
 #include <fcntl.h>
+#include <unistd.h>
 #include "myhdf5.h"
-#include <H5private.h>
 
 SEXP _h5fileLock();