diff -ur adplug-2.2.1-orig/src/s3m.cpp adplug-2.2.1/src/s3m.cpp
--- adplug-2.2.1-orig/src/s3m.cpp 2016-06-12 17:19:33.369934280 +0200
+++ adplug-2.2.1/src/s3m.cpp 2016-06-12 17:32:36.190932642 +0200
@@ -25,7 +25,7 @@
#include <cstring>
#include "s3m.h"
-const char Cs3mPlayer::chnresolv[] = // S3M -> adlib channel conversion
+const signed char Cs3mPlayer::chnresolv[] = // S3M -> adlib channel conversion
{-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,0,1,2,3,4,5,6,7,8,-1,-1,-1,-1,-1,-1,-1};
const unsigned short Cs3mPlayer::notetable[12] = // S3M adlib note table
diff -ur adplug-2.2.1-orig/src/s3m.h adplug-2.2.1/src/s3m.h
--- adplug-2.2.1-orig/src/s3m.h 2016-06-12 17:19:33.367934293 +0200
+++ adplug-2.2.1/src/s3m.h 2016-06-12 17:37:14.538154102 +0200
@@ -90,7 +90,7 @@
unsigned char crow,ord,speed,tempo,del,songend,loopstart,loopcnt;
private:
- static const char chnresolv[];
+ static const signed char chnresolv[];
static const unsigned short notetable[12];
static const unsigned char vibratotab[32];