diff --git a/firmware/common/strcasecmp.c b/firmware/common/strcasecmp.c
index 7bd0d61dd5..b9dd6c13c4 100644
--- a/firmware/common/strcasecmp.c
+++ b/firmware/common/strcasecmp.c
@@ -14,15 +14,15 @@ int strcasecmp(const char *s1, const char *s2)
 
 int strncasecmp(const char *s1, const char *s2, size_t n)
 {
-    if(!n)
-      return 0;
-
-    while (n-- != 0 && tolower(*s1) == tolower(*s2)) {
-        if(n == 0 || *s1 == '\0')
-          break;
-        s1++;
-        s2++;
+    int d = 0;
+    
+    for(; n != 0; n--)
+    {
+        int c1 = tolower(*s1++);
+        int c2 = tolower(*s2++);
+        if((d = c1 - c2) != 0 || c2 == '\0')
+            break;
     }
-
-    return tolower(*(unsigned char *) s1) - tolower(*(unsigned char *) s2);
+    
+    return d;
 }