diff --git a/antlib/checkstyle-10.12.4-all.jar b/antlib/checkstyle-9.3-all.jar
similarity index 54%
rename from antlib/checkstyle-10.12.4-all.jar
rename to antlib/checkstyle-9.3-all.jar
index 940791e0e..c67987769 100644
Binary files a/antlib/checkstyle-10.12.4-all.jar and b/antlib/checkstyle-9.3-all.jar differ
diff --git a/checkstyle.xml b/checkstyle.xml
index 07446ab48..096ccc8f0 100644
--- a/checkstyle.xml
+++ b/checkstyle.xml
@@ -16,20 +16,18 @@
     Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
  -->
 
-<module name="Checker">
-  <module name="SuppressWarningsFilter"/>
-
+<module name = "Checker">
   <property name="charset" value="UTF-8"/>
 
   <property name="severity" value="warning"/>
 
   <property name="fileExtensions" value="java, properties, xml"/>
   <!-- Excludes all 'module-info.java' files              -->
-  <!-- See https://checkstyle.org/filefilters/index.html -->
+  <!-- See https://checkstyle.org/config_filefilters.html -->
   <module name="BeforeExecutionExclusionFileFilter">
     <property name="fileNamePattern" value="module\-info\.java$"/>
   </module>
-  <!-- https://checkstyle.org/filters/suppressionfilter.html -->
+  <!-- https://checkstyle.org/config_filters.html#SuppressionFilter -->
   <module name="SuppressionFilter">
     <property name="file" value="${org.checkstyle.google.suppressionfilter.config}"
            default="checkstyle-suppressions.xml" />
@@ -37,7 +35,7 @@
   </module>
 
   <!-- Checks for whitespace                               -->
-  <!-- See http://checkstyle.org/checks/whitespace/index.html -->
+  <!-- See http://checkstyle.org/config_whitespace.html -->
   <module name="FileTabCharacter">
     <property name="eachLine" value="true"/>
   </module>
@@ -97,7 +95,7 @@
       <property name="tokens"
                value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
                     INSTANCE_INIT, ANNOTATION_DEF, ENUM_DEF, INTERFACE_DEF, RECORD_DEF,
-                    COMPACT_CTOR_DEF, LITERAL_SWITCH"/>
+                    COMPACT_CTOR_DEF"/>
     </module>
     <module name="SuppressionXpathSingleFilter">
       <!-- suppresion is required till https://github.com/checkstyle/checkstyle/issues/7541 -->
@@ -107,10 +105,8 @@
     </module>
     <module name="WhitespaceAfter">
       <property name="tokens"
-               value="COMMA, SEMI, TYPECAST, LITERAL_IF, LITERAL_ELSE, LITERAL_RETURN,
-                    LITERAL_WHILE, LITERAL_DO, LITERAL_FOR, LITERAL_FINALLY, DO_WHILE, ELLIPSIS,
-                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_CATCH, LAMBDA,
-                    LITERAL_YIELD, LITERAL_CASE"/>
+               value="COMMA, SEMI, TYPECAST, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_WHILE, LITERAL_DO, LITERAL_FOR, DO_WHILE"/>
     </module>
     <module name="WhitespaceAround">
       <property name="allowEmptyConstructors" value="true"/>
@@ -128,8 +124,7 @@
                     NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR,
                     SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT, TYPE_EXTENSION_AND"/>
       <message key="ws.notFollowed"
-              value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks
-               may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+              value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
       <message key="ws.notPreceded"
               value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
     </module>
@@ -331,13 +326,13 @@
       <property name="forbiddenSummaryFragments"
                value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
     </module>-->
-    <!-- <module name="JavadocParagraph"/> -->
+    <!-- <module name="JavadocParagraph"/>
     <module name="RequireEmptyLineBeforeBlockTagGroup"/>
     <module name="AtclauseOrder">
       <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
       <property name="target"
                value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
-    </module>
+    </module>-->
     <module name="JavadocMethod">
       <property name="accessModifiers" value="public"/>
       <property name="allowMissingParamTags" value="true"/>
@@ -358,37 +353,24 @@
                 value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
                       RECORD_DEF, ANNOTATION_DEF"/>
       <property name="excludeScope" value="nothing"/>
-    </module>-->
-    <!--<module name="MethodName">
-      <property name="format" value="^[a-z][a-z0-9]\w*$"/>
+    </module>
+    <module name="MethodName">
+      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
       <message key="name.invalidPattern"
              value="Method name ''{0}'' must match pattern ''{1}''."/>
-    </module>-->
-    <module name="SingleLineJavadoc"/>
+    </module>
+    <module name="SingleLineJavadoc"/>-->
     <module name="EmptyCatchBlock">
       <property name="exceptionVariableName" value="expected"/>
     </module>
     <module name="CommentsIndentation">
       <property name="tokens" value="SINGLE_LINE_COMMENT, BLOCK_COMMENT_BEGIN"/>
     </module>
-    <!-- https://checkstyle.org/filters/suppressionxpathfilter.html -->
+    <!-- https://checkstyle.org/config_filters.html#SuppressionXpathFilter -->
     <module name="SuppressionXpathFilter">
       <property name="file" value="${org.checkstyle.google.suppressionxpathfilter.config}"
              default="checkstyle-xpath-suppressions.xml" />
       <property name="optional" value="true"/>
     </module>
-    <module name="SuppressWarningsHolder" />
-    <module name="SuppressionCommentFilter">
-      <property name="offCommentFormat" value="CHECKSTYLE.OFF\: ([\w\|]+)" />
-      <property name="onCommentFormat" value="CHECKSTYLE.ON\: ([\w\|]+)" />
-      <property name="checkFormat" value="$1" />
-    </module>
-    <module name="SuppressWithNearbyCommentFilter">
-      <property name="commentFormat" value="CHECKSTYLE.SUPPRESS\: ([\w\|]+)"/>
-      <!-- $1 refers to the first match group in the regex defined in commentFormat -->
-      <property name="checkFormat" value="$1"/>
-      <!-- The check is suppressed in the next line of code after the comment -->
-      <property name="influenceFormat" value="1"/>
-    </module>
   </module>
 </module>