diff --git a/tag_database b/tag_database
index 45af1e960..5eb4c145c 100644
--- a/tag_database
+++ b/tag_database
@@ -56,6 +56,7 @@ isDivisible:math
 isEven:math
 isFunction:utility
 isNumber:utility
+isPrime:math
 isString:utility
 isSymbol:utility
 JSONToDate:date