diff --git a/scsh/syscalls1.c b/scsh/syscalls1.c
index 0207351..5e905b6 100644
--- a/scsh/syscalls1.c
+++ b/scsh/syscalls1.c
@@ -71,10 +71,12 @@ s48_value wait_pid(s48_value s48_pid, s48_value s48_flags)
 
   result_pid = waitpid(pid, &status, flags);
   if (result_pid == -1)
-      s48_raise_os_error_2 (errno, s48_pid, s48_flags);
-
-  sch_result_pid = s48_enter_integer (result_pid);
-  sch_status = s48_enter_integer (status);
+    if (errno == ECHILD) sch_result_pid = s48_enter_fixnum (0);
+    else s48_raise_os_error_2 (errno, s48_pid, s48_flags);
+  else {
+    sch_result_pid = s48_enter_integer (result_pid);
+    sch_status = s48_enter_integer (status);
+  }
   sch_status_list = s48_cons (sch_status, S48_NULL);
   sch_retval = s48_cons (sch_result_pid, sch_status_list);
   
@@ -124,8 +126,8 @@ s48_value scheme_exec(s48_value prog, s48_value argv, s48_value env)
   }
   s48_stop_alarm_interrupts();
   execve(s48_extract_string (prog), unix_argv, unix_env); /* Do it. */
-  s48_start_alarm_interrupts();
   e = errno;
+  s48_start_alarm_interrupts(); 
   if( env != S48_TRUE ) {
     Free(unix_env);
   }