diff --git a/m-core.h b/m-core.h
index 1f0fbb31..652f0757 100644
--- a/m-core.h
+++ b/m-core.h
@@ -2123,7 +2123,8 @@ m_core_hash (const void *str, size_t length)
 #define M_LETI_SINGLE2(cont, oplist, name)                              \
   for(M_GET_TYPE oplist name;                                           \
       cont && (M_GET_INIT oplist (name), true);                         \
-      (M_GET_CLEAR oplist (name), cont = false))
+      (M_GET_CLEAR oplist (name), cont = false))                        \
+    for(;cont;cont = false)
 
 /* Transform the va list by adding their number as the first argument of
    the list.
diff --git a/tests/test-mcore.c b/tests/test-mcore.c
index 367218be..bd4e45b1 100644
--- a/tests/test-mcore.c
+++ b/tests/test-mcore.c
@@ -173,6 +173,8 @@ static void test_let(void)
 {
   M_LET(z, M_CLASSIC_OPLIST(testobj)) {
     testobj_add(z,z,z);
+    break;
+    assert(0);
   }
 }