diff --git a/SConstruct b/SConstruct
index e6b632a73e..ec14f71390 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1090,8 +1090,8 @@ if conf.CheckCHeader('/System/Library/Frameworks/CoreAudio.framework/Versions/A/
     subst_dict['%JACK_INPUT%'] = "coreaudio:Built-in Audio:in"
     subst_dict['%JACK_OUTPUT%'] = "coreaudio:Built-in Audio:out"
 else:
-    subst_dict['%JACK_INPUT%'] = "alsa_pcm:playback_"
-    subst_dict['%JACK_OUTPUT%'] = "alsa_pcm:capture_"
+    subst_dict['%JACK_INPUT%'] = "system:playback_"
+    subst_dict['%JACK_OUTPUT%'] = "system:capture_"
 
 # posix_memalign available
 if not conf.CheckFunc('posix_memalign'):
diff --git a/libs/midi++2/midi++/jackcompat.h b/libs/midi++2/midi++/jackcompat.h
index f1b748ea66..bf179f7333 100644
--- a/libs/midi++2/midi++/jackcompat.h
+++ b/libs/midi++2/midi++/jackcompat.h
@@ -18,7 +18,7 @@
 #ifndef JACK_COMPAT_H
 #define JACK_COMPAT_H
 
-#define JACK_MIDI_NEEDS_NFRAMES
+//#define JACK_MIDI_NEEDS_NFRAMES
 
 #if defined(JACK_MIDI_NEEDS_NFRAMES)