2 files changed, 2 insertions, 2 deletions
diff --git a/wtf8.c b/wtf8.c
index 68de1ca..09cb9b3 100644
--- a/wtf8.c
+++ b/wtf8.c
@@ -4,7 +4,7 @@
  * Check if first two bits of the character are "10", meaning it's a UTF-8
  * continuation character
  */
-int is_utf8_cont(char c) {
+int is_utf8_cont(unsigned char c) {
     return (c & 0xC0) == 0x80;
 }
 
diff --git a/wtf8.h b/wtf8.h
index c4241a8..5a80f30 100644
--- a/wtf8.h
+++ b/wtf8.h
@@ -1,6 +1,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-int is_utf8_cont(char);
+int is_utf8_cont(unsigned char);
 void print_octets(char *);
 void print_characters(char *);