--- src/file.c
+++ src/file.c	2013-09-30 00:00:00.000000000 +0000
@@ -195,6 +195,8 @@ main(int argc, char *argv[])
 			flags |= MAGIC_DEBUG|MAGIC_CHECK;
 			break;
 		case 'e':
+			if (!optarg)
+				usage();
 			for (i = 0; i < sizeof(nv) / sizeof(nv[0]); i++)
 				if (strcmp(nv[i].name, optarg) == 0)
 					break;
@@ -206,7 +208,7 @@ main(int argc, char *argv[])
 			break;
 
 		case 'f':
-			if(action)
+			if(action || !optarg)
 				usage();
 			if (magic == NULL)
 				if ((magic = load(magicfile, flags)) == NULL)
@@ -215,6 +217,8 @@ main(int argc, char *argv[])
 			++didsomefiles;
 			break;
 		case 'F':
+			if (!optarg)
+				usage();
 			separator = optarg;
 			break;
 		case 'i':
@@ -227,6 +231,8 @@ main(int argc, char *argv[])
 			action = FILE_LIST;
 			break;
 		case 'm':
+			if (!optarg)
+				usage();
 			magicfile = optarg;
 			break;
 		case 'n':