diff --git a/src/ezstream.c b/src/ezstream.c
index 0bff301..d7ae5c6 100644
--- a/src/ezstream.c
+++ b/src/ezstream.c
@@ -304,7 +304,7 @@ openResource(stream_t stream, const char *fileName, int *popenFlag,
 	if (p != NULL)
 		strlcpy(extension, p, sizeof(extension));
 	for (p = extension; *p != '\0'; p++)
-		*p = tolower((int)*p);
+		*p = (char)tolower((int)*p);
 
 	if (strlen(extension) == 0) {
 		log_error("%s: cannot determine file type", fileName);
diff --git a/src/util.c b/src/util.c
index 2c828db..de01b59 100644
--- a/src/util.c
+++ b/src/util.c
@@ -235,10 +235,10 @@ util_strrcasecmp(const char *s, const char *sub)
 	int	 ret;
 
 	for (p = s_cpy; *p != '\0'; p++)
-		*p = tolower((int)*p);
+		*p = (char)tolower((int)*p);
 
 	for (p = sub_cpy; *p != '\0'; p++)
-		*p = tolower((int)*p);
+		*p = (char)tolower((int)*p);
 
 	ret = util_strrcmp(s_cpy, sub_cpy);