diff --git a/src/simulate/simulate.cpp b/src/simulate/simulate.cpp
index e50f4dce6..06b5b8ba5 100644
--- a/src/simulate/simulate.cpp
+++ b/src/simulate/simulate.cpp
@@ -657,9 +657,13 @@ namespace das
         while ( cond->evalBool(context) && !context.stopFlags ) {
             SimNode ** __restrict body = list;
         loopbegin:;
-            for (; body!=tail; ++body) {
-                (*body)->eval(context);
-                DAS_PROCESS_LOOP_FLAGS(break);
+            if (body!=tail) {
+                for (; body!=tail; ++body) {
+                    (*body)->eval(context);
+                    DAS_PROCESS_LOOP_FLAGS(break);
+                }
+            } else {
+                DAS_KEEPALIVE_LOOP(&context);
             }
         }
     loopend:;
@@ -676,10 +680,14 @@ namespace das
         while ( cond->evalBool(context) && !context.stopFlags ) {
             SimNode ** __restrict body = list;
         loopbegin:;
-            for (; body!=tail; ++body) {
-                DAS_SINGLE_STEP(context,(*body)->debugInfo,true);
-                (*body)->eval(context);
-                DAS_PROCESS_LOOP_FLAGS(break);
+            if (body!=tail) {
+                for (; body!=tail; ++body) {
+                    DAS_SINGLE_STEP(context,(*body)->debugInfo,true);
+                    (*body)->eval(context);
+                    DAS_PROCESS_LOOP_FLAGS(break);
+                }
+            } else {
+                DAS_KEEPALIVE_LOOP(&context);
             }
         }
     loopend:;