diff --git a/lib/bitmap.c b/lib/bitmap.c
index eb21456..f549176 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -546,6 +546,7 @@
 					return -EINVAL;
 				b = 0;
 				in_range = 1;
+				at_start = 1;
 				continue;
 			}
 
@@ -558,6 +559,9 @@
 			at_start = 0;
 			totaldigits++;
 		}
+		/* if no digit is after '-', it's wrong*/
+		if (at_start && in_range)
+			return -EINVAL;
 		if (!(a <= b))
 			return -EINVAL;
 		if (b >= nmaskbits)