diff --git a/system/cu/cu_main.c b/system/cu/cu_main.c
index bb6b6d7a1..6252667ca 100644
--- a/system/cu/cu_main.c
+++ b/system/cu/cu_main.c
@@ -446,13 +446,16 @@ int main(int argc, FAR char *argv[])
 
   while (!cu->force_exit)
     {
-      int ch = getc(stdin);
+      char ch;
+      int c = getc(stdin);
 
-      if (ch < 0)
+      if (c < 0)
         {
           continue;
         }
 
+      ch = c;
+
       if (nobreak == 1)
         {
           write(cu->outfd, &ch, 1);