diff --git a/setup/installer/osx/app/launcher.c b/setup/installer/osx/app/launcher.c
index c36909efde..6a668f97af 100644
--- a/setup/installer/osx/app/launcher.c
+++ b/setup/installer/osx/app/launcher.c
@@ -12,6 +12,6 @@ static const char PYVER[] = "**PYVER**";
 
 int 
 main(int argc, const char **argv, const char **envp) {
-    return run(ENV_VARS, ENV_VAR_VALS, PROGRAM, MODULE, FUNCTION, PYVER, argc, argv, envp);
+    return run(ENV_VARS, ENV_VAR_VALS, PROGRAM, MODULE, FUNCTION, PYVER, **IS_GUI**, argc, argv, envp);
 }
 
diff --git a/setup/installer/osx/app/main.py b/setup/installer/osx/app/main.py
index 117bbc613a..6e711f9246 100644
--- a/setup/installer/osx/app/main.py
+++ b/setup/installer/osx/app/main.py
@@ -10,6 +10,7 @@ import sys, os, shutil, plistlib, subprocess, glob, zipfile, tempfile, \
     py_compile, stat, operator, time
 from functools import partial
 from contextlib import contextmanager
+from itertools import repeat
 
 abspath, join, basename = os.path.abspath, os.path.join, os.path.basename
 
@@ -92,8 +93,8 @@ def compile_launchers(contents_dir, xprograms, pyver):
     src = src.replace('/*ENV_VARS*/', env)
     src = src.replace('/*ENV_VAR_VALS*/', env_vals)
     programs = [lib]
-    for program, x in xprograms.items():
-        module, func = x
+    for program, x in xprograms.iteritems():
+        module, func, ptype = x
         info('\tCompiling', program)
         out = join(contents_dir, 'MacOS', program)
         programs.append(out)
@@ -101,6 +102,7 @@ def compile_launchers(contents_dir, xprograms, pyver):
         psrc = psrc.replace('**MODULE**', module)
         psrc = psrc.replace('**FUNCTION**', func)
         psrc = psrc.replace('**PYVER**', pyver)
+        psrc = psrc.replace('**IS_GUI**', ('1' if ptype == 'gui' else '0'))
         fsrc = '/tmp/%s.c'%program
         with open(fsrc, 'wb') as f:
             f.write(psrc)
@@ -230,9 +232,9 @@ class Py2App(object):
         programs = {}
         progs = []
         for x in ('console', 'gui'):
-            progs += list(zip(basenames[x], main_modules[x], main_functions[x]))
-        for program, module, func in progs:
-            programs[program] = (module, func)
+            progs += list(zip(basenames[x], main_modules[x], main_functions[x], repeat(x)))
+        for program, module, func, ptype in progs:
+            programs[program] = (module, func, ptype)
         programs = compile_launchers(self.contents_dir, programs,
                 self.version_info)
         for out in programs:
diff --git a/setup/installer/osx/app/site.py b/setup/installer/osx/app/site.py
index a0b408f728..f38fe6cf77 100644
--- a/setup/installer/osx/app/site.py
+++ b/setup/installer/osx/app/site.py
@@ -31,7 +31,7 @@ for dir in sys.path:
     # if they only differ in case); turn relative paths into absolute
     # paths.
     dir, dircase = makepath(dir)
-    if not dircase in _dirs_in_sys_path:
+    if dircase not in _dirs_in_sys_path:
         L.append(dir)
         _dirs_in_sys_path[dircase] = 1
 sys.path[:] = L
@@ -55,7 +55,7 @@ def addsitedir(sitedir):
     else:
         reset = 0
     sitedir, sitedircase = makepath(sitedir)
-    if not sitedircase in _dirs_in_sys_path:
+    if sitedircase not in _dirs_in_sys_path:
         sys.path.append(sitedir)        # Add path component
     try:
         names = os.listdir(sitedir)
@@ -92,7 +92,7 @@ def addpackage(sitedir, name):
         if dir[-1] == '\n':
             dir = dir[:-1]
         dir, dircase = makepath(sitedir, dir)
-        if not dircase in _dirs_in_sys_path and os.path.exists(dir):
+        if dircase not in _dirs_in_sys_path and os.path.exists(dir):
             sys.path.append(dir)
             _dirs_in_sys_path[dircase] = 1
     if reset:
@@ -184,8 +184,15 @@ def setup_asl():
 
 def main():
     global __file__
-    base = sys.resourcepath
 
+    if sys.calibre_is_gui_app and not (
+            sys.stdout.isatty() or sys.stderr.isatty() or sys.stdin.isatty()):
+        try:
+            setup_asl()
+        except:
+            pass  # Failure to log to Console.app is not critical
+
+    base = sys.resourcepath
     sys.frozen = 'macosx_app'
     sys.new_app_bundle = True
     abs__file__()
@@ -193,16 +200,4 @@ def main():
     add_calibre_vars(base)
     addsitedir(sys.site_packages)
 
-    launched_by_launch_services = False
-
-    for arg in tuple(sys.argv[1:]):
-        if arg.startswith('-psn_'):
-            sys.argv.remove(arg)
-            launched_by_launch_services = True
-    if launched_by_launch_services:
-        try:
-            setup_asl()
-        except:
-            pass  # Failure to log to Console.app is not critical
-
     return run_entry_point()
diff --git a/setup/installer/osx/app/util.c b/setup/installer/osx/app/util.c
index b8e1e360fd..c7d390af45 100644
--- a/setup/installer/osx/app/util.c
+++ b/setup/installer/osx/app/util.c
@@ -46,7 +46,7 @@ set_env_vars(const char **ENV_VARS, const char **ENV_VAR_VALS, const char* exe_p
 }
 
 void initialize_interpreter(const char **ENV_VARS, const char **ENV_VAR_VALS,
-        char *PROGRAM, const char *MODULE, const char *FUNCTION, const char *PYVER,
+        char *PROGRAM, const char *MODULE, const char *FUNCTION, const char *PYVER, int IS_GUI,
         const char* exe_path, const char *rpath, int argc, const char **argv) {
     PyObject *pargv, *v;
     int i;
@@ -83,6 +83,7 @@ void initialize_interpreter(const char **ENV_VARS, const char **ENV_VAR_VALS,
     PySys_SetObject("calibre_basename", PyBytes_FromString(PROGRAM));
     PySys_SetObject("calibre_module", PyBytes_FromString(MODULE));
     PySys_SetObject("calibre_function", PyBytes_FromString(FUNCTION));
+    PySys_SetObject("calibre_is_gui_app", ((IS_GUI) ? Py_True : Py_False));
     PySys_SetObject("resourcepath", PyBytes_FromString(rpath));
     snprintf(path, 3000, "%s/site-packages", pyhome);
     PySys_SetObject("site_packages", PyBytes_FromString(pyhome));
@@ -154,7 +155,7 @@ EXPORT
 int
 run(const char **ENV_VARS, const char **ENV_VAR_VALS, char *PROGRAM,
         const char *MODULE, const char *FUNCTION, const char *PYVER,
-        int argc, const char **argv, const char **envp) {
+        int IS_GUI, int argc, const char **argv, const char **envp) {
     char *pathPtr = NULL, *t = NULL;
     char buf[3*PATH_MAX];
     int ret = 0, i;
@@ -190,7 +191,7 @@ run(const char **ENV_VARS, const char **ENV_VAR_VALS, char *PROGRAM,
     char rpath[PATH_MAX+1], exe_path[PATH_MAX+1];
     snprintf(exe_path, PATH_MAX+1, "%s/Contents", pathPtr);
     snprintf(rpath, PATH_MAX+1, "%s/Resources", exe_path);
-    initialize_interpreter(ENV_VARS, ENV_VAR_VALS, PROGRAM, MODULE, FUNCTION, PYVER,
+    initialize_interpreter(ENV_VARS, ENV_VAR_VALS, PROGRAM, MODULE, FUNCTION, PYVER, IS_GUI,
             exe_path, rpath, argc, argv);
 
     site = PyImport_ImportModule("site");
diff --git a/setup/installer/osx/app/util.h b/setup/installer/osx/app/util.h
index 636af4db13..5b5dfc0453 100644
--- a/setup/installer/osx/app/util.h
+++ b/setup/installer/osx/app/util.h
@@ -1,5 +1,5 @@
 #pragma once
 
 int run(const char **ENV_VARS, const char **ENV_VAR_VALS, char *PROGRAM,
-        const char *MODULE, const char *FUNCTION, const char *PYVER,
+        const char *MODULE, const char *FUNCTION, const char *PYVER, int IS_GUI,
         int argc, const char **argv, const char **envp);