diff --git a/epan/to_str-int.h b/epan/to_str-int.h
index 6294613abc..d42d941ca7 100644
--- a/epan/to_str-int.h
+++ b/epan/to_str-int.h
@@ -81,7 +81,7 @@ char *qword_to_hex_punct(char *out, guint64 qword, char punct);
  * String is not NUL terminated by this routine.
  * There needs to be at least len * 3 - 1 bytes in the buffer.
  */
-char *bytes_to_hexstr_punct(char *out, const guint8 *ad, guint32 len, char punct);
+char *bytes_to_hexstr_punct(char *out, const guint8 *ad, size_t len, char punct);
 
 /**
  * oct_to_str_back()
diff --git a/epan/to_str.c b/epan/to_str.c
index f3420c055e..ba63669beb 100644
--- a/epan/to_str.c
+++ b/epan/to_str.c
@@ -134,9 +134,9 @@ qword_to_hex_punct(char *out, guint64 qword, char punct)
  * There needs to be at least len * 2 bytes left in the buffer.
  */
 char *
-bytes_to_hexstr(char *out, const guint8 *ad, guint32 len)
+bytes_to_hexstr(char *out, const guint8 *ad, size_t len)
 {
-	guint32 i;
+	size_t i;
 
 	if (!ad)
 		REPORT_DISSECTOR_BUG("Null pointer passed to bytes_to_hexstr()");
@@ -155,9 +155,9 @@ bytes_to_hexstr(char *out, const guint8 *ad, guint32 len)
  * There needs to be at least len * 3 - 1 bytes left in the buffer.
  */
 char *
-bytes_to_hexstr_punct(char *out, const guint8 *ad, guint32 len, char punct)
+bytes_to_hexstr_punct(char *out, const guint8 *ad, size_t len, char punct)
 {
-	guint32 i;
+	size_t i;
 
 	if (!ad)
 		REPORT_DISSECTOR_BUG("Null pointer passed to bytes_to_hexstr_punct()");
@@ -181,10 +181,10 @@ bytes_to_hexstr_punct(char *out, const guint8 *ad, guint32 len, char punct)
  * the resulting string is (len-1) bytes shorter)
  */
 gchar *
-bytestring_to_str(wmem_allocator_t *scope, const guint8 *ad, const guint32 len, const char punct)
+bytestring_to_str(wmem_allocator_t *scope, const guint8 *ad, size_t len, const char punct)
 {
 	gchar *buf;
-	guint32 buflen = len;
+	size_t buflen = len;
 	gchar *buf_ptr;
 	int truncated = 0;
 
@@ -215,7 +215,7 @@ bytestring_to_str(wmem_allocator_t *scope, const guint8 *ad, const guint32 len,
 }
 
 char *
-bytes_to_str(wmem_allocator_t *scope, const guint8 *bd, int bd_len)
+bytes_to_str(wmem_allocator_t *scope, const guint8 *bd, size_t bd_len)
 {
 	gchar *cur;
 	gchar *cur_ptr;
@@ -225,7 +225,7 @@ bytes_to_str(wmem_allocator_t *scope, const guint8 *bd, int bd_len)
 		REPORT_DISSECTOR_BUG("Null pointer passed to bytes_to_str()");
 
 	cur=(gchar *)wmem_alloc(scope, MAX_BYTE_STR_LEN+3+1);
-	if (bd_len <= 0) { cur[0] = '\0'; return cur; }
+	if (bd_len == 0) { cur[0] = '\0'; return cur; }
 
 	if (bd_len > MAX_BYTE_STR_LEN/2) {	/* bd_len > 24 */
 		truncated = 1;
diff --git a/epan/to_str.h b/epan/to_str.h
index 08e0203661..4798bcc8cf 100644
--- a/epan/to_str.h
+++ b/epan/to_str.h
@@ -175,7 +175,7 @@ WS_DLL_PUBLIC char *dword_to_hex(char *out, guint32 dword);
  * @param bd_len The length of the byte array
  * @return A pointer to the formatted string
  */
-WS_DLL_PUBLIC char *bytes_to_str(wmem_allocator_t *scope, const guint8 *bd, int bd_len);
+WS_DLL_PUBLIC char *bytes_to_str(wmem_allocator_t *scope, const guint8 *bd, size_t bd_len);
 
 /** Turn an array of bytes into a string showing the bytes in hex,
  *  separated by a punctuation character.
@@ -188,7 +188,7 @@ WS_DLL_PUBLIC char *bytes_to_str(wmem_allocator_t *scope, const guint8 *bd, int
  *
  * @see bytes_to_str()
  */
-WS_DLL_PUBLIC gchar *bytestring_to_str(wmem_allocator_t *scope, const guint8 *ad, const guint32 len, const char punct);
+WS_DLL_PUBLIC gchar *bytestring_to_str(wmem_allocator_t *scope, const guint8 *ad, size_t len, const char punct);
 
 /**
  * bytes_to_hexstr()
@@ -199,7 +199,7 @@ WS_DLL_PUBLIC gchar *bytestring_to_str(wmem_allocator_t *scope, const guint8 *ad
  * String is not NUL terminated by this routine.
  * There needs to be at least len * 2 bytes in the buffer.
  */
-WS_DLL_PUBLIC char *bytes_to_hexstr(char *out, const guint8 *ad, guint32 len);
+WS_DLL_PUBLIC char *bytes_to_hexstr(char *out, const guint8 *ad, size_t len);
 
 /**
  * uint_to_str_back()