diff --git a/src/utils.ts b/src/utils.ts
index 8f19cb9..ff5bcf2 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -85,9 +85,12 @@ export function parseDimIndex(spec: string, count: number): string[] {
         const start = parts[0];
         const end = parts[1];
 
-        if (!start || !end) {
+        if (start === undefined || end === undefined) {
             return [];
         }
+        if (start < 0 || end < 0 || end < start) {
+            throw new Error('dimIndex Element Range Spec invalid.');
+        }
 
         const numElements = end - start + 1;
         if (numElements < count) {