1 files changed, 1 insertions, 1 deletions
diff --git a/src/H5CS.c b/src/H5CS.c
index f429d98..3fccce4 100644
--- a/src/H5CS.c
+++ b/src/H5CS.c
@@ -145,7 +145,7 @@ H5CS_print_stack(const H5CS_t *fstack, FILE *stream)
 
     HDfprintf(stream, "HDF5-DIAG: Function stack from %s ", H5_lib_vers_info_g);
     /* try show the process or thread id in multiple processes cases*/
-    HDfprintf(stream, "thread %lu.", H5TS_thread_id());
+    HDfprintf(stream, "thread %" PRIu64 ".", H5TS_thread_id());
     if(fstack && fstack->nused>0)
         HDfprintf(stream, "  Back trace follows.");
     HDfputc('\n', stream);