diff --git a/src/include/h5core/h5_core.h b/src/include/h5core/h5_core.h
index cae7dc5..8112000 100644
--- a/src/include/h5core/h5_core.h
+++ b/src/include/h5core/h5_core.h
@@ -143,7 +143,7 @@ done:									\
 #endif
 
 #include <hdf5.h>
-#if defined(H5_HAVE_PARALLEL)
+#if defined(H5_HAVE_PARALLEL) && !defined(PARALLEL_IO)
 #define PARALLEL_IO 1
 #endif