diff --git a/apps/upper_case.cpp b/apps/upper_case.cpp
index 7852eba6e3..fb08f1210f 100644
--- a/apps/upper_case.cpp
+++ b/apps/upper_case.cpp
@@ -235,7 +235,7 @@ int main(int argc, char **argv) {
             boinc_crash();
         }
         if (early_sleep && i>30) {
-            g_sleep = true;
+            boinc_disable_timer_thread = true;
             while (1) boinc_sleep(1);
         }