diff --git a/src/exchange-lib/test_exchange_api.c b/src/exchange-lib/test_exchange_api.c
index 102c37b08..34e9da83b 100644
--- a/src/exchange-lib/test_exchange_api.c
+++ b/src/exchange-lib/test_exchange_api.c
@@ -585,6 +585,11 @@ struct Command
        */
       struct GNUNET_OS_Process *aggregator_proc;
 
+      /**
+       * ID of task called whenever we get a SIGCHILD.
+       */
+      struct GNUNET_SCHEDULER_Task *child_death_task;
+
     } run_aggregator;
 
     struct {
@@ -681,12 +686,6 @@ struct InterpreterState
  */
 static struct GNUNET_DISK_PipeHandle *sigpipe;
 
-/**
- * ID of task called whenever we get a SIGCHILD.
- */
-static struct GNUNET_SCHEDULER_Task *child_death_task;
-
-
 
 /**
  * The testcase failed, return with an error code.
@@ -1266,7 +1265,7 @@ maint_child_death (void *cls)
   const struct GNUNET_DISK_FileHandle *pr;
   char c[16];
 
-  child_death_task = NULL;
+  cmd->details.run_aggregator.child_death_task = NULL;
   pr = GNUNET_DISK_pipe_handle (sigpipe, GNUNET_DISK_PIPE_END_READ);
   GNUNET_break (0 < GNUNET_DISK_file_read (pr, &c, sizeof (c)));
   GNUNET_OS_process_wait (cmd->details.run_aggregator.aggregator_proc);
@@ -2233,9 +2232,10 @@ interpreter_run (void *cls)
         return;
       }
       pr = GNUNET_DISK_pipe_handle (sigpipe, GNUNET_DISK_PIPE_END_READ);
-      child_death_task = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
-                                                         pr,
-                                                         &maint_child_death, is);
+      cmd->details.run_aggregator.child_death_task
+        = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
+                                          pr,
+                                          &maint_child_death, is);
       return;
     }
   case OC_CHECK_BANK_TRANSFER:
@@ -2547,6 +2547,11 @@ do_shutdown (void *cls)
         GNUNET_OS_process_destroy (cmd->details.run_aggregator.aggregator_proc);
         cmd->details.run_aggregator.aggregator_proc = NULL;
       }
+      if (NULL != cmd->details.run_aggregator.child_death_task)
+      {
+        GNUNET_SCHEDULER_cancel (cmd->details.run_aggregator.child_death_task);
+        cmd->details.run_aggregator.child_death_task = NULL;
+      }
       break;
     case OC_CHECK_BANK_TRANSFER:
       break;