2 files changed, 4 insertions, 4 deletions
diff --git a/nuttx/lib/lib_strcasecmp.c b/nuttx/lib/lib_strcasecmp.c
index 425a3e639..d9c5e5636 100644
--- a/nuttx/lib/lib_strcasecmp.c
+++ b/nuttx/lib/lib_strcasecmp.c
@@ -54,10 +54,10 @@
 #ifndef CONFIG_ARCH_STRCMP
 int strcasecmp(const char *cs, const char *ct)
 {
-  register signed char result;
+  register int result;
   for (;;)
     {
-      if ((result = toupper(*cs) - toupper(*ct)) != 0 || !*cs)
+      if ((result = (int)toupper(*cs) - (int)toupper(*ct)) != 0 || !*cs)
         {
           break;
         }
diff --git a/nuttx/lib/lib_strncasecmp.c b/nuttx/lib/lib_strncasecmp.c
index 5b35bfff1..c34396a50 100644
--- a/nuttx/lib/lib_strncasecmp.c
+++ b/nuttx/lib/lib_strncasecmp.c
@@ -54,10 +54,10 @@
 #ifndef CONFIG_ARCH_STRNCASECMP
 int strncasecmp(const char *cs, const char *ct, size_t nb)
 {
-  register signed char result = 0;
+  register int result = 0;
   for (; nb > 0; nb--)
     {
-      if ((result = toupper(*cs) - toupper(*ct)) != 0 || !*cs)
+      if ((result = (int)toupper(*cs) - (int)toupper(*ct)) != 0 || !*cs)
         {
           break;
         }