diff --git a/Makefile b/Makefile
index 18475d6..77fff73 100644
--- a/Makefile
+++ b/Makefile
@@ -51,7 +51,7 @@ EXTRA_OUTPUT_FILES :=
 LIBRARY_DIRS := $(DEVKITPRO)/libctru $(DEVKITPRO)/portlibs/armv6k
 LIBRARIES := mpg123 opusfile opus ogg ctru m
 
-BUILD_FLAGS :=
+BUILD_FLAGS := -Wall -Wextra
 RUN_FLAGS :=
 
 VERSION_PARTS := $(subst ., ,$(shell git describe --tags --abbrev=0))
diff --git a/source/all.h b/source/all.h
index 89c4901..b7ef44f 100644
--- a/source/all.h
+++ b/source/all.h
@@ -1,9 +1,6 @@
 #include <errno.h>
 #include <stdio.h>
 
-/* Channel to play music on */
-#define CHANNEL	0x08
-
 /* Adds extra debugging text */
 //#define DEBUG
 
@@ -14,13 +11,3 @@
 
 #define delete(ptr) \
 	free((void*) ptr); ptr = NULL
-
-struct decoder_fn
-{
-	int (* init)(const char* file);
-	uint32_t (* rate)(void);
-	uint8_t (* channels)(void);
-	int buffSize;
-	uint64_t (* decode)(void*);
-	void (* exit)(void);
-};
diff --git a/source/flac.c b/source/flac.c
index 6368fea..49f922c 100644
--- a/source/flac.c
+++ b/source/flac.c
@@ -3,11 +3,11 @@
 #define DR_FLAC_IMPLEMENTATION
 #include <./dr_libs/dr_flac.h>
 
-#include "all.h"
 #include "flac.h"
+#include "playback.h"
 
 static drflac*		pFlac;
-static const int	buffSize = 16 * 1024;
+static const size_t	buffSize = 16 * 1024;
 
 /**
  * Set decoder parameters for flac.
diff --git a/source/flac.h b/source/flac.h
index dc734c9..5da31ec 100644
--- a/source/flac.h
+++ b/source/flac.h
@@ -1,3 +1,5 @@
+#include "playback.h"
+
 /**
  * Set decoder parameters for flac.
  *
diff --git a/source/mp3.c b/source/mp3.c
index 3cc1f3a..2535a22 100644
--- a/source/mp3.c
+++ b/source/mp3.c
@@ -4,10 +4,10 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "all.h"
 #include "mp3.h"
+#include "playback.h"
 
-static int*				buffSize;
+static size_t*				buffSize;
 static mpg123_handle	*mh = NULL;
 static uint32_t			rate;
 static uint8_t			channels;
diff --git a/source/mp3.h b/source/mp3.h
index 06218ca..223440a 100644
--- a/source/mp3.h
+++ b/source/mp3.h
@@ -1,3 +1,5 @@
+#include "playback.h"
+
 /**
  * Set decoder parameters for MP3.
  *
diff --git a/source/opus.c b/source/opus.c
index 8e98d88..2285f9d 100644
--- a/source/opus.c
+++ b/source/opus.c
@@ -2,12 +2,12 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "all.h"
 #include "opus.h"
+#include "playback.h"
 
 static OggOpusFile*		opusFile;
 static const OpusHead*	opusHead;
-static const int		buffSize = 32 * 1024;
+static const size_t		buffSize = 32 * 1024;
 
 /**
  * Set decoder parameters for Opus.
diff --git a/source/opus.h b/source/opus.h
index 98e2c09..4e88f02 100644
--- a/source/opus.h
+++ b/source/opus.h
@@ -1,4 +1,5 @@
 #include <opus/opusfile.h>
+#include "playback.h"
 
 void setOpus(struct decoder_fn* decoder);
 
diff --git a/source/playback.c b/source/playback.c
index 8a81b34..109b6d6 100644
--- a/source/playback.c
+++ b/source/playback.c
@@ -1,4 +1,5 @@
 #include <3ds.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -49,7 +50,7 @@ bool isPlaying(void)
 static int getFileType(const char *file)
 {
 	FILE* ftest = fopen(file, "rb");
-	int fileSig = 0;
+	uint32_t fileSig;
 	enum file_types file_type = FILE_TYPE_ERROR;
 
 	/* Failure opening file */
@@ -83,7 +84,7 @@ static int getFileType(const char *file)
 			break;
 
 		// "OggS"
-		case 0x5367674f:
+		case 0x5367674F:
 			if(isOpus(file) == 0)
 				file_type = FILE_TYPE_OPUS;
 			else
@@ -161,7 +162,7 @@ void playFile(void* infoIn)
 			goto err;
 	}
 
-	if(R_FAILED(ndspInit()))
+	if(ndspInit() < 0)
 	{
 		errno = NDSP_INIT_FAIL;
 		goto err;
diff --git a/source/playback.h b/source/playback.h
index 4779f58..60f0d24 100644
--- a/source/playback.h
+++ b/source/playback.h
@@ -1,6 +1,9 @@
 #ifndef ctrmus_playback_h
 #define ctrmus_playback_h
 
+/* Channel to play music on */
+#define CHANNEL	0x08
+
 enum file_types
 {
 	FILE_TYPE_ERROR = -1,
@@ -11,6 +14,16 @@ enum file_types
 	FILE_TYPE_MP3
 };
 
+struct decoder_fn
+{
+	int (* init)(const char* file);
+	uint32_t (* rate)(void);
+	uint8_t (* channels)(void);
+	size_t buffSize;
+	uint64_t (* decode)(void*);
+	void (* exit)(void);
+};
+
 struct playbackInfo_t
 {
 	char*				file;
diff --git a/source/wav.c b/source/wav.c
index e27f9dc..c21f700 100644
--- a/source/wav.c
+++ b/source/wav.c
@@ -3,10 +3,10 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "all.h"
 #include "wav.h"
+#include "playback.h"
 
-static const int	buffSize	= 16 * 1024;
+static const size_t	buffSize	= 16 * 1024;
 static FILE*		pWav		= NULL;
 static char			header[45];
 static uint8_t		channels;
diff --git a/source/wav.h b/source/wav.h
index 5971c21..6814a94 100644
--- a/source/wav.h
+++ b/source/wav.h
@@ -1,3 +1,5 @@
+#include "playback.h"
+
 /**
  * Set decoder parameters for WAV.
  *