diff --git a/tools/fit_check_sign.c b/tools/fit_check_sign.c
index af257cc..e1198bc 100644
--- a/tools/fit_check_sign.c
+++ b/tools/fit_check_sign.c
@@ -62,6 +62,15 @@ int main(int argc, char **argv)
 			break;
 	}
 
+	if (!fdtfile) {
+		fprintf(stderr, "%s: Missing fdt file\n", *argv);
+		usage(*argv);
+	}
+	if (!keyfile) {
+		fprintf(stderr, "%s: Missing key file\n", *argv);
+		usage(*argv);
+	}
+
 	ffd = mmap_fdt(cmdname, fdtfile, 0, &fit_blob, &fsbuf, false);
 	if (ffd < 0)
 		return EXIT_FAILURE;
diff --git a/tools/fit_info.c b/tools/fit_info.c
index afbed7b..481ac6d 100644
--- a/tools/fit_info.c
+++ b/tools/fit_info.c
@@ -68,6 +68,18 @@ int main(int argc, char **argv)
 			break;
 		}
 
+	if (!fdtfile) {
+		fprintf(stderr, "%s: Missing fdt file\n", *argv);
+		usage(*argv);
+	}
+	if (!nodename) {
+		fprintf(stderr, "%s: Missing node name\n", *argv);
+		usage(*argv);
+	}
+	if (!propertyname) {
+		fprintf(stderr, "%s: Missing property name\n", *argv);
+		usage(*argv);
+	}
 	ffd = mmap_fdt(cmdname, fdtfile, 0, &fit_blob, &fsbuf, false);
 
 	if (ffd < 0) {