diff --git a/gnu-c/temperatures.c b/gnu-c/temperatures.c
index 6e341c2..a185598 100644
--- a/gnu-c/temperatures.c
+++ b/gnu-c/temperatures.c
@@ -14,11 +14,12 @@ double f2c(double fahrenheit) {
 }
 
 
-void usage(const char *prog, const char *msg) {
-    fprintf(stderr, "Usage: %s <temp>[fFcC]\n", prog);
+void die_usage(const char *prog, const char *msg) {
+    fprintf(stderr, "Usage: %s <temp>[FC]\n", prog);
     if (msg != NULL) {
         fprintf(stderr, "%s\n", msg);
     }
+    exit(EXIT_FAILURE);
 }
 
 
@@ -33,8 +34,7 @@ int main(int argc, char * argv[]) {
     const char *temp_string;
 
     if (argc < 2) {
-        usage(prog, NULL);
-        exit(EXIT_FAILURE);
+        die_usage(prog, NULL);
     }
 
     if (((int)strlen(argv[1]) == 1) && (argv[1][0] == '-')) {
@@ -45,28 +45,23 @@ int main(int argc, char * argv[]) {
     }
 
     if ((ret == 0) || (ret == EOF)) {
-        usage(prog, "No temperature provided!");
-        exit(EXIT_FAILURE);
+        die_usage(prog, "No temperature provided!");
     }
 
     if (ret == 1) {
-        usage(prog, "No scale provided!");
-        exit(EXIT_FAILURE);
+        die_usage(prog, "No scale provided!");
     }
 
     switch (scale) {
-        case 'c':
         case 'C':
             printf(out_fmt, c2f(temp), 'F');
             break;
-        case 'f':
         case 'F':
             printf(out_fmt, f2c(temp), 'C');
             break;
         default:
             sprintf(msg, "Unknown scale: '%c'", scale);
-            usage(prog, msg);
-            break;
+            die_usage(prog, msg);
     }
 
     exit(EXIT_SUCCESS);