diff --git a/Implementierung/lib/md2_impls/md2_common.h b/Implementierung/lib/md2_impls/md2_common.h
index 663c0d4..80a014f 100644
--- a/Implementierung/lib/md2_impls/md2_common.h
+++ b/Implementierung/lib/md2_impls/md2_common.h
@@ -126,6 +126,6 @@ void md2_second_loop(uint8_t* messageDigestBuf);
  * @param messageDigestBuf the message digest buffer
  * @param i the index of the 16-byte message block
  */
-void md2_first_loop(const uint8_t* buf, uint8_t* messageDigestBuf, int i);
+void md2_first_loop(const uint8_t* buf, uint8_t* messageDigestBuf, size_t i);
 
 #endif  // MD2_COMMON_H
\ No newline at end of file
diff --git a/Implementierung/src/md2_impls/md2_common.c b/Implementierung/src/md2_impls/md2_common.c
index 7128922..04dcf0e 100644
--- a/Implementierung/src/md2_impls/md2_common.c
+++ b/Implementierung/src/md2_impls/md2_common.c
@@ -117,7 +117,7 @@ void md2_second_loop(uint8_t* messageDigestBuf) {
   SECOND_LOOP_END_MARK
 }
 
-void md2_first_loop(const uint8_t* buf, uint8_t* messageDigestBuf, int i) {
+void md2_first_loop(const uint8_t* buf, uint8_t* messageDigestBuf, size_t i) {
   FIRST_LOOP_START_MARK
   for (int j = 0; j < 16; j++) {
     messageDigestBuf[16 + j] = buf[i * 16 + j];