diff --git a/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/token/CreateTokenRequest.java b/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/token/CreateTokenRequest.java
index aa28605d0fd..5956e1a6613 100644
--- a/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/token/CreateTokenRequest.java
+++ b/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/token/CreateTokenRequest.java
@@ -142,7 +142,7 @@ public final class CreateTokenRequest extends ActionRequest {
             out.writeOptionalString(refreshToken);
         } else {
             if ("refresh_token".equals(grantType)) {
-                throw new UnsupportedOperationException("a refresh request cannot be sent to an older version");
+                throw new IllegalArgumentException("a refresh request cannot be sent to an older version");
             } else {
                 out.writeString(username);
                 final byte[] passwordBytes = CharArrays.toUtf8Bytes(password.getChars());
diff --git a/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/token/InvalidateTokenRequest.java b/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/token/InvalidateTokenRequest.java
index 8ad4f024eaf..7a8372fe456 100644
--- a/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/token/InvalidateTokenRequest.java
+++ b/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/token/InvalidateTokenRequest.java
@@ -74,7 +74,7 @@ public final class InvalidateTokenRequest extends ActionRequest {
         if (out.getVersion().onOrAfter(Version.V_6_2_0)) {
             out.writeVInt(tokenType.ordinal());
         } else if (tokenType == Type.REFRESH_TOKEN) {
-            throw new UnsupportedOperationException("refresh token invalidation cannot be serialized with version [" + out.getVersion() +
+            throw new IllegalArgumentException("refresh token invalidation cannot be serialized with version [" + out.getVersion() +
                     "]");
         }
     }