diff --git a/tailbone/static/js/numeric.js b/tailbone/static/js/numeric.js
index 50bf5eb0..31573ce5 100644
--- a/tailbone/static/js/numeric.js
+++ b/tailbone/static/js/numeric.js
@@ -19,6 +19,12 @@ function key_modifies(event) {
     } else if (event.which >= 96 && event.which <= 105) { // Numeric (10-Key)
         return true;
 
+    } else if (event.which == 173) {                    // hyphen (negative sign)
+        return true;
+
+    } else if (event.which == 190) {                    // period/decimal
+        return true;
+
     } else if (event.which == 8) {                      // Backspace
         return true;