diff --git a/main.go b/main.go
index 94c43ba..602008e 100644
--- a/main.go
+++ b/main.go
@@ -382,11 +382,8 @@ func shuntingYard(re string) []postfixNode {
 			}
 
 			idx := len(outQueue) - 1
-			// Get the most recently added non-paren node
-			for node := outQueue[idx]; idx >= 0 && (node.nodetype == RPAREN || node.nodetype == LPAREN); node = outQueue[idx] {
-				idx--
-			}
-			if idx < 0 {
+			// Get the last added node
+			if idx < 0 || outQueue[idx].nodetype == LPAREN {
 				panic("Numeric specifier with no content.")
 			}
 			outQueue[idx].startReps = startRangeNum