diff --git a/audio_ao.c b/audio_ao.c
index 67a51ea1..c1d7a3d0 100644
--- a/audio_ao.c
+++ b/audio_ao.c
@@ -49,7 +49,8 @@ static int init(int argc, char **argv) {
 
     optind = 0;
     // some platforms apparently require optreset = 1; - which?
-    char opt, *mid;
+    int opt;
+    char *mid;
     while ((opt = getopt(argc, argv, "d:i:n:o:")) > 0) {
         switch (opt) {
             case 'd':
diff --git a/shairport.c b/shairport.c
index b38808e5..1138405b 100644
--- a/shairport.c
+++ b/shairport.c
@@ -73,7 +73,7 @@ void usage(char *progname) {
 }
 
 int parse_options(int argc, char **argv) {
-    char opt;
+    int opt;
     while ((opt = getopt(argc, argv, "+hvp:a:o:b:")) > 0) {
         switch (opt) {
             default: