diff --git a/libdnet-stripped/NMAP_MODIFICATIONS b/libdnet-stripped/NMAP_MODIFICATIONS
index c433ad4e6..60472da5b 100644
--- a/libdnet-stripped/NMAP_MODIFICATIONS
+++ b/libdnet-stripped/NMAP_MODIFICATIONS
@@ -422,6 +422,34 @@ Index: src/intf.c
  	ret = 0;
  	while (fgets(buf, sizeof(buf), fp) != NULL) {
 
+o Added casts to calls of ctype functions so that their arguments are explicitly
+cast to (int) [Josh Marlow]
+Index: src/blob.c
+===================================================================
+--- src/blob.c	(revision 14763)
++++ src/blob.c	(working copy)
+@@ -162,7 +162,7 @@
+ 	for (p = (char *)fmt; *p != '\0'; p++) {
+ 		if (*p == '%') {
+ 			p++;
+-			if (isdigit((int)*p)) {
++			if (isdigit((int) (unsigned char) *p)) {
+ 				len = strtol(p, &p, 10);
+ 			} else if (*p == '*') {
+ 				len = va_arg(*ap, int);
+Index: src/intf-win32.c
+===================================================================
+--- src/intf-win32.c	(revision 14763)
++++ src/intf-win32.c	(working copy)
+@@ -234,7 +234,7 @@
+ 	char *p = (char *)device;
+ 	int n, type = _ifcombo_type(device);
+ 	
+-	while (isalpha(*p)) p++;
++	while (isalpha((int) (unsigned char) *p)) p++;
+ 	n = atoi(p);
+ 
+ 	return (intf->ifcombo[type].idx[n]);
 
 
 ===CHANGES ALREADY MERGED TO UPSTREAM LIBDNET GO BELOW THIS LINE===
diff --git a/libdnet-stripped/src/blob.c b/libdnet-stripped/src/blob.c
index 2db9ae415..57ff0c3af 100644
--- a/libdnet-stripped/src/blob.c
+++ b/libdnet-stripped/src/blob.c
@@ -162,7 +162,7 @@ blob_fmt(blob_t *b, int pack, const char *fmt, va_list *ap)
 	for (p = (char *)fmt; *p != '\0'; p++) {
 		if (*p == '%') {
 			p++;
-			if (isdigit((int)*p)) {
+			if (isdigit((int) (unsigned char) *p)) {
 				len = strtol(p, &p, 10);
 			} else if (*p == '*') {
 				len = va_arg(*ap, int);
diff --git a/libdnet-stripped/src/intf-win32.c b/libdnet-stripped/src/intf-win32.c
index 032bec977..c19edcb1c 100644
--- a/libdnet-stripped/src/intf-win32.c
+++ b/libdnet-stripped/src/intf-win32.c
@@ -234,7 +234,7 @@ _find_ifindex(intf_t *intf, const char *device)
 	char *p = (char *)device;
 	int n, type = _ifcombo_type(device);
 	
-	while (isalpha(*p)) p++;
+	while (isalpha((int) (unsigned char) *p)) p++;
 	n = atoi(p);
 
 	return (intf->ifcombo[type].idx[n]);