diff --git a/22-malloc/libc/string.c b/22-malloc/libc/string.c
index 9b8a6d3..eb587c2 100644
--- a/22-malloc/libc/string.c
+++ b/22-malloc/libc/string.c
@@ -25,17 +25,13 @@ void hex_to_ascii(int n, char str[]) {
 
     s32 tmp;
     int i;
-    for (i = 28; i > 0; i -= 4) {
+    for (i = 28; i >= 0; i -= 4) {
         tmp = (n >> i) & 0xF;
         if (tmp == 0 && zeros == 0) continue;
         zeros = 1;
-        if (tmp > 0xA) append(str, tmp - 0xA + 'a');
+        if (tmp >= 0xA) append(str, tmp - 0xA + 'a');
         else append(str, tmp + '0');
     }
-
-    tmp = n & 0xF;
-    if (tmp >= 0xA) append(str, tmp - 0xA + 'a');
-    else append(str, tmp + '0');
 }
 
 /* K&R */
diff --git a/23-fixes/libc/string.c b/23-fixes/libc/string.c
index 688f4a5..9c2f399 100644
--- a/23-fixes/libc/string.c
+++ b/23-fixes/libc/string.c
@@ -25,17 +25,13 @@ void hex_to_ascii(int n, char str[]) {
 
     int32_t tmp;
     int i;
-    for (i = 28; i > 0; i -= 4) {
+    for (i = 28; i >= 0; i -= 4) {
         tmp = (n >> i) & 0xF;
         if (tmp == 0 && zeros == 0) continue;
         zeros = 1;
-        if (tmp > 0xA) append(str, tmp - 0xA + 'a');
+        if (tmp >= 0xA) append(str, tmp - 0xA + 'a');
         else append(str, tmp + '0');
     }
-
-    tmp = n & 0xF;
-    if (tmp >= 0xA) append(str, tmp - 0xA + 'a');
-    else append(str, tmp + '0');
 }
 
 /* K&R */