diff --git a/runtime/parsec/control/runtime_control.c b/runtime/parsec/control/runtime_control.c
index 4719ff7a2eb56e88418642b2d97e5e1d53559e0c..b69f7d8c8bcc8742ed1a5ca716590afe8a2e2778 100644
--- a/runtime/parsec/control/runtime_control.c
+++ b/runtime/parsec/control/runtime_control.c
@@ -144,7 +144,7 @@ int RUNTIME_comm_rank( CHAM_context_t *chamctxt )
  */
 int RUNTIME_comm_size( CHAM_context_t *chamctxt )
 {
-    int size = 0;
+    int size = 1;
 #if defined(CHAMELEON_USE_MPI)
     MPI_Comm_size(MPI_COMM_WORLD, &size);
 #endif