diff --git a/src/auto/configure b/src/auto/configure
index b42f601..27aea9c 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -12004,7 +12004,7 @@
 	getpwent getpwnam getpwuid getrlimit gettimeofday getwd lstat memcmp \
 	memset mkdtemp nanosleep opendir putenv qsort readlink select setenv \
 	setpgid setsid sigaltstack sigstack sigset sigsetjmp sigaction \
-	sigvec strcasecmp strerror strftime stricmp strncasecmp \
+	sigprocmask sigvec strcasecmp strerror strftime stricmp strncasecmp \
 	strnicmp strpbrk strtol tgetent towlower towupper iswupper \
 	usleep utime utimes
 do :
diff --git a/src/config.h.in b/src/config.h.in
index 9d35e48..62427e2 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -190,6 +190,7 @@
 #undef HAVE_SIGSET
 #undef HAVE_SIGSETJMP
 #undef HAVE_SIGSTACK
+#undef HAVE_SIGPROCMASK
 #undef HAVE_SIGVEC
 #undef HAVE_SMACK
 #undef HAVE_STRCASECMP
diff --git a/src/configure.in b/src/configure.in
index c0a60b2..43bf9ad 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -3598,7 +3598,7 @@
 	getpwent getpwnam getpwuid getrlimit gettimeofday getwd lstat memcmp \
 	memset mkdtemp nanosleep opendir putenv qsort readlink select setenv \
 	setpgid setsid sigaltstack sigstack sigset sigsetjmp sigaction \
-	sigvec strcasecmp strerror strftime stricmp strncasecmp \
+	sigprocmask sigvec strcasecmp strerror strftime stricmp strncasecmp \
 	strnicmp strpbrk strtol tgetent towlower towupper iswupper \
 	usleep utime utimes)
 AC_FUNC_FSEEKO
diff --git a/src/os_unix.c b/src/os_unix.c
index bc9acd4..0569184 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -211,6 +211,15 @@
 static void catch_int_signal(void);
 static void set_signals(void);
 static void catch_signals(RETSIGTYPE (*func_deadly)(), RETSIGTYPE (*func_other)());
+#ifdef HAVE_SIGPROCMASK
+# define SIGSET_DECL(set)	sigset_t set;
+# define BLOCK_SIGNALS(set)	block_signals(set)
+# define UNBLOCK_SIGNALS(set)	unblock_signals(set)
+#else
+# define SIGSET_DECL(set)
+# define BLOCK_SIGNALS(set)	do { /**/ } while (0)
+# define UNBLOCK_SIGNALS(set)	do { /**/ } while (0)
+#endif
 static int  have_wildcard(int, char_u **);
 static int  have_dollars(int, char_u **);
 
@@ -1468,6 +1477,33 @@
 	    signal(signal_info[i].sig, func_other);
 }
 
+#ifdef HAVE_SIGPROCMASK
+    static void
+block_signals(sigset_t *set)
+{
+    sigset_t	newset;
+    int		i;
+
+    sigemptyset(&newset);
+
+    for (i = 0; signal_info[i].sig != -1; i++)
+	sigaddset(&newset, signal_info[i].sig);
+
+# if defined(_REENTRANT) && defined(SIGCONT)
+    /* SIGCONT isn't in the list, because its default action is ignore */
+    sigaddset(&newset, SIGCONT);
+# endif
+
+    sigprocmask(SIG_BLOCK, &newset, set);
+}
+
+    static void
+unblock_signals(sigset_t *set)
+{
+    sigprocmask(SIG_SETMASK, set, NULL);
+}
+#endif
+
 /*
  * Handling of SIGHUP, SIGQUIT and SIGTERM:
  * "when" == a signal:       when busy, postpone and return FALSE, otherwise
@@ -4283,12 +4319,18 @@
 
     if (!pipe_error)			/* pty or pipe opened or not used */
     {
+	SIGSET_DECL(curset)
+
 # ifdef __BEOS__
 	beos_cleanup_read_thread();
 # endif
 
-	if ((pid = fork()) == -1)	/* maybe we should use vfork() */
+	BLOCK_SIGNALS(&curset);
+	pid = fork();	/* maybe we should use vfork() */
+	if (pid == -1)
 	{
+	    UNBLOCK_SIGNALS(&curset);
+
 	    MSG_PUTS(_("\nCannot fork\n"));
 	    if ((options & (SHELL_READ|SHELL_WRITE))
 # ifdef FEAT_GUI
@@ -4315,6 +4357,7 @@
 	else if (pid == 0)	/* child */
 	{
 	    reset_signals();		/* handle signals normally */
+	    UNBLOCK_SIGNALS(&curset);
 
 	    if (!show_shell_mess || (options & SHELL_EXPAND))
 	    {
@@ -4458,6 +4501,7 @@
 	     */
 	    catch_signals(SIG_IGN, SIG_ERR);
 	    catch_int_signal();
+	    UNBLOCK_SIGNALS(&curset);
 
 	    /*
 	     * For the GUI we redirect stdin, stdout and stderr to our window.
@@ -5069,6 +5113,7 @@
     int		use_file_for_out = options->jo_io[PART_OUT] == JIO_FILE;
     int		use_file_for_err = options->jo_io[PART_ERR] == JIO_FILE;
     int		use_out_for_err = options->jo_io[PART_ERR] == JIO_OUT;
+    SIGSET_DECL(curset)
 
     if (use_out_for_err && use_null_for_out)
 	use_null_for_err = TRUE;
@@ -5140,13 +5185,14 @@
 	    goto failed;
     }
 
+    BLOCK_SIGNALS(&curset);
     pid = fork();	/* maybe we should use vfork() */
-    if (pid  == -1)
+    if (pid == -1)
     {
 	/* failed to fork */
+	UNBLOCK_SIGNALS(&curset);
 	goto failed;
     }
-
     if (pid == 0)
     {
 	int	null_fd = -1;
@@ -5154,6 +5200,7 @@
 
 	/* child */
 	reset_signals();		/* handle signals normally */
+	UNBLOCK_SIGNALS(&curset);
 
 # ifdef HAVE_SETSID
 	/* Create our own process group, so that the child and all its
@@ -5234,6 +5281,8 @@
     }
 
     /* parent */
+    UNBLOCK_SIGNALS(&curset);
+
     job->jv_pid = pid;
     job->jv_status = JOB_STARTED;
     job->jv_channel = channel;  /* ch_refcount was set above */
@@ -5357,7 +5406,6 @@
 	}
     }
     return NULL;
-
 }
 
     int
diff --git a/src/testdir/test_channel.vim b/src/testdir/test_channel.vim
index e7ba667..0a50ed4 100644
--- a/src/testdir/test_channel.vim
+++ b/src/testdir/test_channel.vim
@@ -1433,6 +1433,21 @@
   call assert_fails('call job_start("")', 'E474:')
 endfunc
 
+func Test_job_stop_immediately()
+  if !has('job')
+    return
+  endif
+
+  let job = job_start([s:python, '-c', 'import time;time.sleep(10)'])
+  try
+    call job_stop(job)
+    call WaitFor('"dead" == job_status(job)')
+    call assert_equal('dead', job_status(job))
+  finally
+    call job_stop(job, 'kill')
+  endtry
+endfunc
+
 " This was leaking memory.
 func Test_partial_in_channel_cycle()
   let d = {}
diff --git a/src/version.c b/src/version.c
index 80a837a..b157520 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    45,
+/**/
     44,
 /**/
     43,