diff --git a/include/fluidsynth/midi.h b/include/fluidsynth/midi.h
index bd991a0a..5108c6b3 100644
--- a/include/fluidsynth/midi.h
+++ b/include/fluidsynth/midi.h
@@ -31,7 +31,7 @@ extern "C" {
  */
 
 FLUIDSYNTH_API fluid_midi_event_t* new_fluid_midi_event(void);
-FLUIDSYNTH_API int delete_fluid_midi_event(fluid_midi_event_t* event);
+FLUIDSYNTH_API void delete_fluid_midi_event(fluid_midi_event_t* event);
 
 FLUIDSYNTH_API int fluid_midi_event_set_type(fluid_midi_event_t* evt, int type);
 FLUIDSYNTH_API int fluid_midi_event_get_type(fluid_midi_event_t* evt);
@@ -84,7 +84,7 @@ typedef int (*handle_midi_event_func_t)(void* data, fluid_midi_event_t* event);
 FLUIDSYNTH_API fluid_midi_router_t* new_fluid_midi_router(fluid_settings_t* settings,
 						       handle_midi_event_func_t handler, 
 						       void* event_handler_data); 
-FLUIDSYNTH_API int delete_fluid_midi_router(fluid_midi_router_t* handler); 
+FLUIDSYNTH_API void delete_fluid_midi_router(fluid_midi_router_t* handler); 
 FLUIDSYNTH_API int fluid_midi_router_set_default_rules (fluid_midi_router_t *router);
 FLUIDSYNTH_API int fluid_midi_router_clear_rules (fluid_midi_router_t *router);
 FLUIDSYNTH_API int fluid_midi_router_add_rule (fluid_midi_router_t *router,
@@ -122,7 +122,7 @@ enum fluid_player_status
 };
 
 FLUIDSYNTH_API fluid_player_t* new_fluid_player(fluid_synth_t* synth);
-FLUIDSYNTH_API int delete_fluid_player(fluid_player_t* player);
+FLUIDSYNTH_API void delete_fluid_player(fluid_player_t* player);
 FLUIDSYNTH_API int fluid_player_add(fluid_player_t* player, const char *midifile);
 FLUIDSYNTH_API int fluid_player_add_mem(fluid_player_t* player, const void *buffer, size_t len);
 FLUIDSYNTH_API int fluid_player_play(fluid_player_t* player);
diff --git a/include/fluidsynth/ramsfont.h b/include/fluidsynth/ramsfont.h
index c4cf9458..3fef94ec 100644
--- a/include/fluidsynth/ramsfont.h
+++ b/include/fluidsynth/ramsfont.h
@@ -58,7 +58,7 @@ int fluid_ramsfont_izone_set_loop(fluid_ramsfont_t* sfont,
 				int on, float loopstart, float loopend);
 
 FLUIDSYNTH_API fluid_sample_t* new_fluid_ramsample(void);
-FLUIDSYNTH_API int delete_fluid_ramsample(fluid_sample_t* sample);
+FLUIDSYNTH_API void delete_fluid_ramsample(fluid_sample_t* sample);
 FLUIDSYNTH_API int fluid_sample_set_name(fluid_sample_t* sample, const char *name);
 FLUIDSYNTH_API 
 int fluid_sample_set_sound_data(fluid_sample_t* sample, short *data, 
diff --git a/include/fluidsynth/synth.h b/include/fluidsynth/synth.h
index fa279ef3..e75c9f62 100644
--- a/include/fluidsynth/synth.h
+++ b/include/fluidsynth/synth.h
@@ -63,7 +63,7 @@ struct _fluid_synth_channel_info_t
 };
 
 FLUIDSYNTH_API fluid_synth_t* new_fluid_synth(fluid_settings_t* settings);
-FLUIDSYNTH_API int delete_fluid_synth(fluid_synth_t* synth);
+FLUIDSYNTH_API void delete_fluid_synth(fluid_synth_t* synth);
 FLUIDSYNTH_API fluid_settings_t* fluid_synth_get_settings(fluid_synth_t* synth);
 
 
diff --git a/src/midi/fluid_midi.h b/src/midi/fluid_midi.h
index fc26c9b3..12e11280 100644
--- a/src/midi/fluid_midi.h
+++ b/src/midi/fluid_midi.h
@@ -28,7 +28,7 @@
 typedef struct _fluid_midi_parser_t fluid_midi_parser_t;
 
 fluid_midi_parser_t* new_fluid_midi_parser(void);
-int delete_fluid_midi_parser(fluid_midi_parser_t* parser);
+void delete_fluid_midi_parser(fluid_midi_parser_t* parser);
 fluid_midi_event_t* fluid_midi_parser_parse(fluid_midi_parser_t* parser, unsigned char c);
 
 
@@ -248,7 +248,7 @@ struct _fluid_track_t {
 typedef struct _fluid_track_t fluid_track_t;
 
 fluid_track_t* new_fluid_track(int num);
-int delete_fluid_track(fluid_track_t* track);
+void delete_fluid_track(fluid_track_t* track);
 int fluid_track_set_name(fluid_track_t* track, char* name);
 char* fluid_track_get_name(fluid_track_t* track);
 int fluid_track_add_event(fluid_track_t* track, fluid_midi_event_t* evt);
diff --git a/src/rvoice/fluid_rev.c b/src/rvoice/fluid_rev.c
index f76b9bcb..28913cf2 100644
--- a/src/rvoice/fluid_rev.c
+++ b/src/rvoice/fluid_rev.c
@@ -9,6 +9,7 @@
   Translated to C by Peter Hanappe, Mai 2001
 */
 
+#include "fluid_sys.h"
 #include "fluid_rev.h"
 
 /***************************************************************
diff --git a/src/sfloader/fluid_ramsfont.c b/src/sfloader/fluid_ramsfont.c
index 43d27eb7..d75eb545 100644
--- a/src/sfloader/fluid_ramsfont.c
+++ b/src/sfloader/fluid_ramsfont.c
@@ -52,7 +52,7 @@ static void fluid_ramsfont_iteration_start (fluid_ramsfont_t* sfont);
 static int fluid_ramsfont_iteration_next (fluid_ramsfont_t* sfont,
                                           fluid_preset_t* preset);
 static fluid_rampreset_t* new_fluid_rampreset(fluid_ramsfont_t* sfont);
-static int delete_fluid_rampreset (fluid_rampreset_t* preset);
+static void delete_fluid_rampreset (fluid_rampreset_t* preset);
 static int fluid_rampreset_get_banknum (fluid_rampreset_t* preset);
 static int fluid_rampreset_get_num (fluid_rampreset_t* preset);
 static const char *fluid_rampreset_get_name (fluid_rampreset_t* preset);
@@ -251,7 +251,7 @@ delete_fluid_ramsfont (fluid_ramsfont_t* sfont)
 {
   fluid_list_t *list;
   fluid_rampreset_t* preset;
-  fluid_return_if_fail(sfont != NULL);
+  fluid_return_val_if_fail(sfont != NULL, FLUID_OK);
 
   /* Check that no samples are currently used */
   for (list = sfont->sample; list; list = fluid_list_next(list)) {
@@ -549,7 +549,7 @@ delete_fluid_rampreset (fluid_rampreset_t* preset)
   zone = preset->zone;
   while (zone != NULL) {
     preset->zone = zone->next;
-    delete_fluid_preset_zone(zone) != FLUID_OK);
+    delete_fluid_preset_zone(zone);
     zone = preset->zone;
   }
 
diff --git a/src/synth/fluid_chan.h b/src/synth/fluid_chan.h
index bf3b5564..034ed40d 100644
--- a/src/synth/fluid_chan.h
+++ b/src/synth/fluid_chan.h
@@ -87,7 +87,7 @@ struct _fluid_channel_t
 
 fluid_channel_t* new_fluid_channel(fluid_synth_t* synth, int num);
 void fluid_channel_init_ctrl(fluid_channel_t* chan, int is_all_ctrl_off);
-int delete_fluid_channel(fluid_channel_t* chan);
+void delete_fluid_channel(fluid_channel_t* chan);
 void fluid_channel_reset(fluid_channel_t* chan);
 int fluid_channel_set_preset(fluid_channel_t* chan, fluid_preset_t* preset);
 fluid_preset_t* fluid_channel_get_preset(fluid_channel_t* chan);
diff --git a/src/synth/fluid_synth.c b/src/synth/fluid_synth.c
index ccf575ba..837fef50 100644
--- a/src/synth/fluid_synth.c
+++ b/src/synth/fluid_synth.c
@@ -503,10 +503,11 @@ fluid_sample_timer_t* new_fluid_sample_timer(fluid_synth_t* synth, fluid_timer_c
 
 void delete_fluid_sample_timer(fluid_synth_t* synth, fluid_sample_timer_t* timer)
 {
+    fluid_sample_timer_t** ptr;
     fluid_return_if_fail(synth != NULL);
     fluid_return_if_fail(timer != NULL);
     
-	fluid_sample_timer_t** ptr = &synth->sample_timers;
+	ptr = &synth->sample_timers;
 	while (*ptr) {
 		if (*ptr == timer) {
 			*ptr = timer->next; 
diff --git a/src/synth/fluid_synth.h b/src/synth/fluid_synth.h
index dabe7650..5433c0fb 100644
--- a/src/synth/fluid_synth.h
+++ b/src/synth/fluid_synth.h
@@ -200,7 +200,7 @@ int fluid_synth_set_chorus_full(fluid_synth_t* synth, int set, int nr, double le
                                 double speed, double depth_ms, int type);
 
 fluid_sample_timer_t* new_fluid_sample_timer(fluid_synth_t* synth, fluid_timer_callback_t callback, void* data);
-int delete_fluid_sample_timer(fluid_synth_t* synth, fluid_sample_timer_t* timer);
+void delete_fluid_sample_timer(fluid_synth_t* synth, fluid_sample_timer_t* timer);
 
 void fluid_synth_api_enter(fluid_synth_t* synth);
 void fluid_synth_api_exit(fluid_synth_t* synth);
diff --git a/src/utils/fluid_list.c b/src/utils/fluid_list.c
index b845a779..19d3b36e 100644
--- a/src/utils/fluid_list.c
+++ b/src/utils/fluid_list.c
@@ -26,6 +26,7 @@
 
 
 
+#include "fluid_sys.h"
 #include "fluid_list.h"
 
 
@@ -42,9 +43,9 @@ new_fluid_list(void)
 void
 delete_fluid_list(fluid_list_t *list)
 {
+  fluid_list_t *next;
   fluid_return_if_fail(list != NULL);
 
-  fluid_list_t *next;
   while (list) {
     next = list->next;
     FLUID_FREE(list);