diff --git a/src/main/java/strman/Strman.java b/src/main/java/strman/Strman.java
index 0504c26..d321d15 100644
--- a/src/main/java/strman/Strman.java
+++ b/src/main/java/strman/Strman.java
@@ -842,6 +842,7 @@ public static String reverse(final String value) {
      */
     public static String rightPad(final String value, String pad, final int length) {
         validate(value, NULL_STRING_PREDICATE, NULL_STRING_MSG_SUPPLIER);
+        validate(pad, v -> v.length() != 1, () -> "'pad' should be only ONE charater");
         if (value.length() > length) {
             return value;
         }