diff --git a/index.html b/index.html
index 1db5d89..c2c219b 100644
--- a/index.html
+++ b/index.html
@@ -95,7 +95,7 @@
this.textarea.id = `${this.name}Input`;
this.textarea.className = "numberInput";
this.textarea.oninput = () => {
- if (this.textarea.value === undefined || this.textarea.value === null)
+ if (this.textarea.value === undefined || this.textarea.value === null || this.textarea.value === "")
return;
this.textarea.value = this.numeralSystem.filterBaseString(this.textarea.value);