diff --git a/src/test/java/org/apache/commons/lang3/LocaleUtilsTest.java b/src/test/java/org/apache/commons/lang3/LocaleUtilsTest.java
index 4adadb4cd65..a1ab5a01052 100644
--- a/src/test/java/org/apache/commons/lang3/LocaleUtilsTest.java
+++ b/src/test/java/org/apache/commons/lang3/LocaleUtilsTest.java
@@ -42,6 +42,7 @@
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
 import org.junitpioneer.jupiter.DefaultLocale;
+import org.junitpioneer.jupiter.ReadsDefaultLocale;
 
 /**
  * Tests for {@link LocaleUtils}.
@@ -194,6 +195,7 @@ private static void assertValidToLocale(
     }
 
     @BeforeEach
+    @ReadsDefaultLocale
     public void setUp() {
         // Testing #LANG-304. Must be called before availableLocaleSet is called.
         LocaleUtils.isAvailableLocale(Locale.getDefault());
@@ -540,6 +542,7 @@ void testToLocale_3Part() {
      * Test toLocale(Locale) method.
      */
     @Test
+    @ReadsDefaultLocale
     void testToLocale_Locale_defaults() {
         assertNull(LocaleUtils.toLocale((String) null));
         assertEquals(Locale.getDefault(), LocaleUtils.toLocale((Locale) null));
diff --git a/src/test/java/org/apache/commons/lang3/StringUtilsContainsTest.java b/src/test/java/org/apache/commons/lang3/StringUtilsContainsTest.java
index 61579a9219f..54eab7a8fc0 100644
--- a/src/test/java/org/apache/commons/lang3/StringUtilsContainsTest.java
+++ b/src/test/java/org/apache/commons/lang3/StringUtilsContainsTest.java
@@ -238,11 +238,8 @@ void testContainsAnyIgnoreCase_StringStringArray() {
     @WritesDefaultLocale
     void testContainsIgnoreCase_LocaleIndependence() {
         final Locale[] locales = { Locale.ENGLISH, new Locale("tr"), Locale.getDefault() };
-
         final String[][] tdata = { { "i", "I" }, { "I", "i" }, { "\u03C2", "\u03C3" }, { "\u03A3", "\u03C2" }, { "\u03A3", "\u03C3" }, };
-
         final String[][] fdata = { { "\u00DF", "SS" }, };
-
         for (final Locale testLocale : locales) {
             Locale.setDefault(testLocale);
             for (int j = 0; j < tdata.length; j++) {
diff --git a/src/test/java/org/apache/commons/lang3/time/FastDateFormatTest.java b/src/test/java/org/apache/commons/lang3/time/FastDateFormatTest.java
index 15895c36367..4023b8e301c 100644
--- a/src/test/java/org/apache/commons/lang3/time/FastDateFormatTest.java
+++ b/src/test/java/org/apache/commons/lang3/time/FastDateFormatTest.java
@@ -46,6 +46,8 @@
 import org.junit.jupiter.api.Test;
 import org.junitpioneer.jupiter.DefaultLocale;
 import org.junitpioneer.jupiter.DefaultTimeZone;
+import org.junitpioneer.jupiter.ReadsDefaultLocale;
+import org.junitpioneer.jupiter.ReadsDefaultTimeZone;
 
 /**
  * Tests {@link FastDateFormat}.
@@ -218,14 +220,14 @@ void test_getInstance_String_TimeZone_Locale() {
     }
 
     @Test
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testCheckDefaults() {
         final FastDateFormat format = FastDateFormat.getInstance();
         final FastDateFormat medium = FastDateFormat.getDateTimeInstance(FastDateFormat.SHORT, FastDateFormat.SHORT);
         assertEquals(medium, format);
-
         final SimpleDateFormat sdf = new SimpleDateFormat();
         assertEquals(sdf.toPattern(), format.getPattern());
-
         assertEquals(Locale.getDefault(), format.getLocale());
         assertEquals(TimeZone.getDefault(), format.getTimeZone());
     }
@@ -246,13 +248,13 @@ void testCheckDifferingStyles() {
     }
 
     @Test
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testDateDefaults() {
         assertEquals(FastDateFormat.getDateInstance(FastDateFormat.LONG, Locale.CANADA),
                 FastDateFormat.getDateInstance(FastDateFormat.LONG, TimeZone.getDefault(), Locale.CANADA));
-
         assertEquals(FastDateFormat.getDateInstance(FastDateFormat.LONG, TimeZones.getTimeZone("America/New_York")),
                 FastDateFormat.getDateInstance(FastDateFormat.LONG, TimeZones.getTimeZone("America/New_York"), Locale.getDefault()));
-
         assertEquals(FastDateFormat.getDateInstance(FastDateFormat.LONG),
                 FastDateFormat.getDateInstance(FastDateFormat.LONG, TimeZone.getDefault(), Locale.getDefault()));
     }
@@ -424,25 +426,25 @@ void testStandaloneShortMonthForm() {
     }
 
     @Test
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testTimeDateDefaults() {
         assertEquals(FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.MEDIUM, Locale.CANADA),
                 FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.MEDIUM, TimeZone.getDefault(), Locale.CANADA));
-
         assertEquals(FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.MEDIUM, TimeZones.getTimeZone("America/New_York")),
                 FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.MEDIUM, TimeZones.getTimeZone("America/New_York"), Locale.getDefault()));
-
         assertEquals(FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.MEDIUM),
                 FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.MEDIUM, TimeZone.getDefault(), Locale.getDefault()));
     }
 
     @Test
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testTimeDefaults() {
         assertEquals(FastDateFormat.getTimeInstance(FastDateFormat.LONG, Locale.CANADA),
                 FastDateFormat.getTimeInstance(FastDateFormat.LONG, TimeZone.getDefault(), Locale.CANADA));
-
         assertEquals(FastDateFormat.getTimeInstance(FastDateFormat.LONG, TimeZones.getTimeZone("America/New_York")),
                 FastDateFormat.getTimeInstance(FastDateFormat.LONG, TimeZones.getTimeZone("America/New_York"), Locale.getDefault()));
-
         assertEquals(FastDateFormat.getTimeInstance(FastDateFormat.LONG),
                 FastDateFormat.getTimeInstance(FastDateFormat.LONG, TimeZone.getDefault(), Locale.getDefault()));
     }
diff --git a/src/test/java/org/apache/commons/lang3/time/FastDateParserTest.java b/src/test/java/org/apache/commons/lang3/time/FastDateParserTest.java
index 04c223ed358..4e07086a64e 100644
--- a/src/test/java/org/apache/commons/lang3/time/FastDateParserTest.java
+++ b/src/test/java/org/apache/commons/lang3/time/FastDateParserTest.java
@@ -253,22 +253,17 @@ void test_Equality_Hash(final TriFunction<String, TimeZone, Locale, DateParser>
     }
 
     @Test
+    @ReadsDefaultLocale
     void test1806() throws ParseException {
         final String formatStub = "yyyy-MM-dd'T'HH:mm:ss.SSS";
         final String dateStub = "2001-02-04T12:08:56.235";
-
         for (final Expected1806 trial : Expected1806.values()) {
             final Calendar cal = initializeCalendar(trial.zone);
-
             final String message = trial.zone.getDisplayName() + ";";
-
             DateParser parser = getInstance(formatStub + "X", trial.zone);
-            assertEquals(cal.getTime().getTime(), parser.parse(dateStub + trial.one).getTime() - trial.offset,
-                message + trial.one);
-
+            assertEquals(cal.getTime().getTime(), parser.parse(dateStub + trial.one).getTime() - trial.offset, message + trial.one);
             parser = getInstance(formatStub + "XX", trial.zone);
             assertEquals(cal.getTime(), parser.parse(dateStub + trial.two), message + trial.two);
-
             parser = getInstance(formatStub + "XXX", trial.zone);
             assertEquals(cal.getTime(), parser.parse(dateStub + trial.three), message + trial.three);
         }
@@ -442,13 +437,12 @@ void testLang303() throws ParseException {
     }
 
     @Test
+    @ReadsDefaultLocale
     void testLang538() throws ParseException {
         final DateParser parser = getInstance("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", TimeZones.GMT);
-
         final Calendar cal = Calendar.getInstance(TimeZones.getTimeZone("GMT-8"));
         cal.clear();
         cal.set(2009, Calendar.OCTOBER, 16, 8, 42, 16);
-
         assertEquals(cal.getTime(), parser.parse("2009-10-16T16:42:16.000Z"));
     }
 
@@ -671,6 +665,8 @@ private void testSdfAndFdp(final TriFunction<String, TimeZone, Locale, DateParse
      * @throws ParseException so we don't have to catch it
      */
     @Test
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testShortDateStyleWithLocales() throws ParseException {
         DateParser fdf = getDateInstance(FastDateFormat.SHORT, Locale.US);
         final Calendar cal = Calendar.getInstance();
@@ -704,15 +700,14 @@ void testSpecialCharacters(final TriFunction<String, TimeZone, Locale, DateParse
     }
 
     @Test
+    @ReadsDefaultLocale
     void testTimeZoneMatches() {
-        final DateParser parser = getInstance(yMdHmsSZ, REYKJAVIK);
-        assertEquals(REYKJAVIK, parser.getTimeZone());
+        assertEquals(REYKJAVIK, getInstance(yMdHmsSZ, REYKJAVIK).getTimeZone());
     }
 
     @Test
     void testToStringContainsName() {
-        final DateParser parser = getInstance(YMD_SLASH);
-        assertTrue(parser.toString().startsWith("FastDate"));
+        assertTrue(getInstance(YMD_SLASH).toString().startsWith("FastDate"));
     }
 
     // we cannot use historic dates to test time zone parsing, some time zones have second offsets
diff --git a/src/test/java/org/apache/commons/lang3/time/FastDateParser_MoreOrLessTest.java b/src/test/java/org/apache/commons/lang3/time/FastDateParser_MoreOrLessTest.java
index 77eae646a16..1754f04d403 100644
--- a/src/test/java/org/apache/commons/lang3/time/FastDateParser_MoreOrLessTest.java
+++ b/src/test/java/org/apache/commons/lang3/time/FastDateParser_MoreOrLessTest.java
@@ -28,12 +28,16 @@
 
 import org.apache.commons.lang3.AbstractLangTest;
 import org.junit.jupiter.api.Test;
+import org.junitpioneer.jupiter.ReadsDefaultLocale;
+import org.junitpioneer.jupiter.ReadsDefaultTimeZone;
 
 class FastDateParser_MoreOrLessTest extends AbstractLangTest {
 
     private static final TimeZone NEW_YORK = TimeZones.getTimeZone("America/New_York");
 
     @Test
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testInputHasLessCharacters() {
         final FastDateParser parser = new FastDateParser("MM/dd/yyy", TimeZone.getDefault(), Locale.getDefault());
         final ParsePosition parsePosition = new ParsePosition(0);
@@ -42,6 +46,8 @@ void testInputHasLessCharacters() {
     }
 
     @Test
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testInputHasMoreCharacters() {
         final FastDateParser parser = new FastDateParser("MM/dd", TimeZone.getDefault(), Locale.getDefault());
         final ParsePosition parsePosition = new ParsePosition(0);
@@ -55,6 +61,8 @@ void testInputHasMoreCharacters() {
     }
 
     @Test
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testInputHasPrecedingCharacters() {
         final FastDateParser parser = new FastDateParser("MM/dd", TimeZone.getDefault(), Locale.getDefault());
         final ParsePosition parsePosition = new ParsePosition(0);
@@ -65,6 +73,8 @@ void testInputHasPrecedingCharacters() {
     }
 
     @Test
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testInputHasWhitespace() {
         final FastDateParser parser = new FastDateParser("M/d/y", TimeZone.getDefault(), Locale.getDefault());
         //SimpleDateFormat parser = new SimpleDateFormat("M/d/y");
@@ -80,6 +90,8 @@ void testInputHasWhitespace() {
     }
 
     @Test
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testInputHasWrongCharacters() {
         final FastDateParser parser = new FastDateParser("MM-dd-yyy", TimeZone.getDefault(), Locale.getDefault());
         final ParsePosition parsePosition = new ParsePosition(0);
diff --git a/src/test/java/org/apache/commons/lang3/time/FastDateParser_TimeZoneStrategyTest.java b/src/test/java/org/apache/commons/lang3/time/FastDateParser_TimeZoneStrategyTest.java
index 3a73dea64a2..7f278f0e7e3 100644
--- a/src/test/java/org/apache/commons/lang3/time/FastDateParser_TimeZoneStrategyTest.java
+++ b/src/test/java/org/apache/commons/lang3/time/FastDateParser_TimeZoneStrategyTest.java
@@ -95,6 +95,7 @@ private String[][] getZoneStringsSorted(final Locale locale) {
      */
     @ParameterizedTest
     @ValueSource(strings = { "ACT", "CST" })
+    @ReadsDefaultLocale
     void testJava25DeprecatedZoneId(final String shortId) throws ParseException {
         final FastDateParser parser = new FastDateParser("dd.MM.yyyy HH:mm:ss z", TimeZone.getTimeZone(shortId), Locale.getDefault());
         final Date date1 = parser.parse("26.10.2014 02:00:00 " + shortId);
diff --git a/src/test/java/org/apache/commons/lang3/time/WeekYearTest.java b/src/test/java/org/apache/commons/lang3/time/WeekYearTest.java
index 1cd47118ce1..42b5e0b1198 100644
--- a/src/test/java/org/apache/commons/lang3/time/WeekYearTest.java
+++ b/src/test/java/org/apache/commons/lang3/time/WeekYearTest.java
@@ -29,6 +29,8 @@
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
+import org.junitpioneer.jupiter.ReadsDefaultLocale;
+import org.junitpioneer.jupiter.ReadsDefaultTimeZone;
 
 class WeekYearTest extends AbstractLangTest {
 
@@ -57,6 +59,8 @@ public static Stream<Arguments> data() {
 
     @ParameterizedTest
     @MethodSource("data")
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testParser(final Calendar vulgar, final String isoForm) {
         final DateParser parser = new FastDateParser("YYYY-'W'ww-u", TimeZone.getDefault(), Locale.getDefault());
 
@@ -71,6 +75,8 @@ void testParser(final Calendar vulgar, final String isoForm) {
 
     @ParameterizedTest
     @MethodSource("data")
+    @ReadsDefaultLocale
+    @ReadsDefaultTimeZone
     void testPrinter(final Calendar vulgar, final String isoForm) {
         final FastDatePrinter printer = new FastDatePrinter("YYYY-'W'ww-u", TimeZone.getDefault(), Locale.getDefault());