diff --git a/src/bsdapm.cc b/src/bsdapm.cc
index 98ded12b..194a5925 100644
--- a/src/bsdapm.cc
+++ b/src/bsdapm.cc
@@ -61,7 +61,7 @@ static int apm_getinfo(int fd, apm_info_t aip) {
   return 0;
 }
 
-void print_apm_adapter(struct text_object *obj, char *p, int p_max_size) {
+void print_apm_adapter(struct text_object *obj, char *p, unsigned int p_max_size) {
   int fd;
   const char *out;
 #ifdef __OpenBSD__
@@ -109,7 +109,7 @@ void print_apm_adapter(struct text_object *obj, char *p, int p_max_size) {
   snprintf(p, p_max_size, "%s", out);
 }
 
-void print_apm_battery_life(struct text_object *obj, char *p, int p_max_size) {
+void print_apm_battery_life(struct text_object *obj, char *p, unsigned int p_max_size) {
   int fd;
   u_int batt_life;
   const char *out;
@@ -150,7 +150,7 @@ void print_apm_battery_life(struct text_object *obj, char *p, int p_max_size) {
   snprintf(p, p_max_size, "%s", out);
 }
 
-void print_apm_battery_time(struct text_object *obj, char *p, int p_max_size) {
+void print_apm_battery_time(struct text_object *obj, char *p, unsigned int p_max_size) {
   int fd;
   int batt_time;
 #ifdef __OpenBSD__
diff --git a/src/bsdapm.h b/src/bsdapm.h
index d7da690b..7201c54a 100644
--- a/src/bsdapm.h
+++ b/src/bsdapm.h
@@ -29,8 +29,8 @@
 #ifndef _BSDAPM_H
 #define _BSDAPM_H
 
-void print_apm_adapter(struct text_object *, char *, int);
-void print_apm_battery_life(struct text_object *, char *, int);
-void print_apm_battery_time(struct text_object *, char *, int);
+void print_apm_adapter(struct text_object *, char *, unsigned int);
+void print_apm_battery_life(struct text_object *, char *, unsigned int);
+void print_apm_battery_time(struct text_object *, char *, unsigned int);
 
 #endif /* _BSDAPM_H */