diff --git a/makefile b/makefile
index 8ee20d2e..882e3950 100644
--- a/makefile
+++ b/makefile
@@ -38,8 +38,16 @@ endif
 
 UNAME := uname
 UNAME_OS := $(shell $(UNAME) -s | cut -f1 -d_)
+$(info UNAME_OS is $(UNAME_OS))
 ifeq ($(findstring CYGWIN,$(UNAME_OS)), CYGWIN)
 	LIB_DIR:=$(shell cygpath -w $(LIB_DIR))
+else ifeq ($(UNAME_OS),OS/390)
+# The issue is still being investigated. See backlog/issues/1424
+# set -Dfile.encoding=IBM-1047 for JDK21+ zOS for now
+ifeq ($(shell test $(JDK_VERSION) -ge 21; echo $$?),0)
+export IBM_JAVA_OPTIONS="-Dfile.encoding=IBM-1047"
+$(info export IBM_JAVA_OPTIONS="-Dfile.encoding=IBM-1047")
+endif
 endif
 
 export LIB_DIR:=$(subst \,/,$(LIB_DIR))
diff --git a/src/org/openj9/envInfo/EnvDetector.java b/src/org/openj9/envInfo/EnvDetector.java
index 67d93cc1..391bf8cf 100644
--- a/src/org/openj9/envInfo/EnvDetector.java
+++ b/src/org/openj9/envInfo/EnvDetector.java
@@ -14,8 +14,10 @@
 
 package org.openj9.envInfo;
 
+import java.io.FileOutputStream;
+import java.io.OutputStreamWriter;
 import java.io.IOException;
-import java.io.Writer;
+import java.io.BufferedWriter;
 
 public class EnvDetector {
 	static boolean isMachineInfo = false;
@@ -78,9 +80,9 @@ private static void getJavaInfo() {
 		/**
 		 * autoGenEnv.mk file will be created to store auto detected java info.
 		 */
-		Writer output = null;
+		BufferedWriter output = null;
 		try {
-			output = Utility.getWriterObject(javaVersionInfo, SPECInfo, "autoGenEnv.mk");
+			output = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("autoGenEnv.mk")));
 			output.write("########################################################\n");
 			output.write("# This is an auto generated file. Please do NOT modify!\n");
 			output.write("########################################################\n");
@@ -92,7 +94,7 @@ private static void getJavaInfo() {
 			output.write(JDK_VENDOR);
 			output.write(TEST_FLAG);
 			output.close();
-			output = Utility.getWriterObject(javaVersionInfo, SPECInfo, "AQACert.log");
+			output = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("AQACert.log")));
 			output.write(JAVA_VERSION);
 			output.write(RELEASE_INFO);
 			output.close();
diff --git a/src/org/openj9/envInfo/Utility.java b/src/org/openj9/envInfo/Utility.java
deleted file mode 100644
index 1873d3d8..00000000
--- a/src/org/openj9/envInfo/Utility.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package org.openj9.envInfo;
-
-import java.io.FileOutputStream;
-import java.io.FileWriter;
-import java.io.IOException;
-import java.io.OutputStreamWriter;
-import java.io.Writer;
-import java.nio.charset.Charset;
-
-public class Utility {
-
-    public static Writer writer;
-
-    public static Writer getWriterObject(int jdkVersion, String SpecInfo, String fileName) {
-		try {
-			if (SpecInfo.toLowerCase().contains("zos") && (jdkVersion >= 21)) {
-				writer = new OutputStreamWriter(new FileOutputStream(fileName, true), Charset.forName("IBM-1047"));
-			} else {
-				writer = new FileWriter(fileName, true);
-			}
-		} catch(IOException e) {
-			e.printStackTrace();
-			System.exit(1);
-		}
-		return writer;
-	}
-}
diff --git a/src/org/testKitGen/MkGen.java b/src/org/testKitGen/MkGen.java
index 3bf84918..6b4fd335 100644
--- a/src/org/testKitGen/MkGen.java
+++ b/src/org/testKitGen/MkGen.java
@@ -14,18 +14,14 @@
 
 package org.testKitGen;
 
+import java.io.FileWriter;
 import java.io.IOException;
-import java.io.Writer;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
-import org.openj9.envInfo.JavaInfo;
-import org.openj9.envInfo.Utility;
-
 public class MkGen {
 	private Arguments arg;
-	private JavaInfo jInfo;
 	private TestTarget tt;
 	private List<String> dirList;
 	private List<String> subdirs;
@@ -34,7 +30,6 @@ public class MkGen {
 
 	public MkGen(Arguments arg, TestTarget tt, PlaylistInfo pli, String makeFile, List<String> dirList, List<String> subdirs) {
 		this.arg = arg;
-		this.jInfo = new JavaInfo();
 		this.tt = tt;
 		this.dirList = dirList;
 		this.subdirs = subdirs;
@@ -51,7 +46,7 @@ public void start() {
 	}
 
 	private void writeVars() {
-		try (Writer f = Utility.getWriterObject(jInfo.getJDKVersion(), arg.getSpec(), makeFile)) {
+		try (FileWriter f = new FileWriter(makeFile)) {
 			String realtiveRoot = "";
 			int subdirlevel = dirList.size();
 			if (subdirlevel == 0) {
@@ -77,7 +72,7 @@ private void writeVars() {
 		}
 	}
 
-	private void writeSingleTest(List<String> testsInPlaylist, TestInfo testInfo, Writer f) throws IOException {
+	private void writeSingleTest(List<String> testsInPlaylist, TestInfo testInfo, FileWriter f) throws IOException {
 		for (Variation var : testInfo.getVars()) {
 			// Generate make target
 			String testTargetName = var.getSubTestName();
@@ -249,7 +244,7 @@ private void writeSingleTest(List<String> testsInPlaylist, TestInfo testInfo, Wr
 	}
 
 	private void writeTargets() {
-		try (Writer f = Utility.getWriterObject(jInfo.getJDKVersion(), arg.getSpec(), makeFile)) {
+		try (FileWriter f = new FileWriter(makeFile, true)) {
 			if (!pli.getIncludeList().isEmpty()) {
 				for (String include : pli.getIncludeList()) {
 					f.write("-include " + include + "\n\n");
diff --git a/src/org/testKitGen/ModesDictionary.java b/src/org/testKitGen/ModesDictionary.java
index 166cf28a..7ddfa383 100644
--- a/src/org/testKitGen/ModesDictionary.java
+++ b/src/org/testKitGen/ModesDictionary.java
@@ -29,14 +29,12 @@
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;
 
-import org.openj9.envInfo.JavaInfo;
 import org.w3c.dom.Element;
 import org.w3c.dom.NodeList;
 import org.xml.sax.SAXException;
 
 public class ModesDictionary {
 	private Arguments arg;
-	private JavaInfo jInfo;
 	private String modesXml;
 	private String ottawaCsv;
 	private Map<String, String> spec2platMap;
@@ -46,7 +44,6 @@ public class ModesDictionary {
 
 	public ModesDictionary(Arguments arg) {
 		this.arg = arg;
-		jInfo = new JavaInfo();
 		modesXml= arg.getProjectRootDir() + "/TKG/" + Constants.MODESXML;
 		ottawaCsv = arg.getProjectRootDir() + "/TKG/" + Constants.OTTAWACSV;
 		spec2platMap = new HashMap<String, String>();
@@ -101,7 +98,7 @@ private void parseInvalidSpec(Element modes) throws IOException {
 		ArrayList<String> specs = new ArrayList<String>();
 		int lineNum = 0;
 		BufferedReader reader = null;
-		if (arg.getSpec().toLowerCase().contains("zos") && !(jInfo.getJDKVersion() >= 21)) {
+		if (arg.getSpec().toLowerCase().contains("zos")) {
 			reader = Files.newBufferedReader(Paths.get(ottawaCsv), Charset.forName("IBM-1047"));
 		} else {
 			reader = Files.newBufferedReader(Paths.get(ottawaCsv));
diff --git a/src/org/testKitGen/UtilsGen.java b/src/org/testKitGen/UtilsGen.java
index cb1ef247..990b4fed 100644
--- a/src/org/testKitGen/UtilsGen.java
+++ b/src/org/testKitGen/UtilsGen.java
@@ -15,18 +15,13 @@
 package org.testKitGen;
 
 import java.io.File;
+import java.io.FileWriter;
 import java.io.IOException;
-import java.io.Writer;
 import java.util.List;
 
-import org.openj9.envInfo.JavaInfo;
-import org.openj9.envInfo.Utility;
-
-
 public class UtilsGen {
 	private Arguments arg;
 	private ModesDictionary md;
-	private JavaInfo jInfo;
 	private String utilsMk;
 	private String rerunMk;
 	private List<String> ignoreOnRerunList;
@@ -34,7 +29,6 @@ public class UtilsGen {
 	public UtilsGen(Arguments arg, ModesDictionary md, List<String> ignoreOnRerunList) {
 		this.arg = arg;
 		this.md = md;
-		this.jInfo = new JavaInfo();
 		this.utilsMk = arg.getProjectRootDir() + "/TKG/" + Constants.UTILSMK;
 		this.rerunMk = arg.getProjectRootDir() + "/TKG/" + Constants.RERUNMK;
 		this.ignoreOnRerunList = ignoreOnRerunList;
@@ -46,7 +40,7 @@ public void generateFiles() {
 	}
 
 	private void generateUtil() {
-		try (Writer f = Utility.getWriterObject(jInfo.getJDKVersion(), arg.getSpec(), utilsMk)) {
+		try (FileWriter f = new FileWriter(utilsMk)) {
 			f.write(Constants.HEADERCOMMENTS);
 			f.write("TOTALCOUNT := " + TestInfo.numOfTests() + "\n");
 			f.write("PLATFORM=\n");
@@ -62,7 +56,7 @@ private void generateUtil() {
 	}
 
 	private void generateRerun() {
-		try (Writer f = Utility.getWriterObject(jInfo.getJDKVersion(), arg.getSpec(), rerunMk)) {
+		try (FileWriter f = new FileWriter(rerunMk)) {
 			f.write(Constants.HEADERCOMMENTS);
 			String ignoreOnRerunStr = String.join(",", ignoreOnRerunList);
 			f.write("IGNORE_ON_RERUN=");