diff --git a/tools/mkimage.c b/tools/mkimage.c
index 8f8b6df37cd112a6788c21e1d75c9ab401bdb870..facebcdf5abff6990d5ce7431f3526ceeb17526f 100644
--- a/tools/mkimage.c
+++ b/tools/mkimage.c
@@ -129,7 +129,7 @@ int main(int argc, char **argv)
 			case 'a':
 				if (--argc <= 0)
 					usage ();
-				params.addr = strtoul (*++argv, &ptr, 16);
+				params.addr = strtoull(*++argv, &ptr, 16);
 				if (*ptr) {
 					fprintf (stderr,
 						"%s: invalid load address %s\n",
@@ -146,7 +146,7 @@ int main(int argc, char **argv)
 			case 'e':
 				if (--argc <= 0)
 					usage ();
-				params.ep = strtoul (*++argv, &ptr, 16);
+				params.ep = strtoull(*++argv, &ptr, 16);
 				if (*ptr) {
 					fprintf (stderr,
 						"%s: invalid entry point %s\n",