diff --git a/src/main/java/org/apache/commons/lang3/math/NumberUtils.java b/src/main/java/org/apache/commons/lang3/math/NumberUtils.java
index 92dcd4fcf..7a90fef6f 100644
--- a/src/main/java/org/apache/commons/lang3/math/NumberUtils.java
+++ b/src/main/java/org/apache/commons/lang3/math/NumberUtils.java
@@ -874,7 +874,7 @@ public class NumberUtils {
      *            can be null)
      * @return true if the magnitude is zero
      */
-    private static boolean isZero(final String mant, String dec) {
+    private static boolean isZero(final String mant, final String dec) {
         return isAllZeros(mant) && isAllZeros(dec);
     }
 
diff --git a/src/test/java/org/apache/commons/lang3/math/NumberUtilsTest.java b/src/test/java/org/apache/commons/lang3/math/NumberUtilsTest.java
index 971bd5c52..d7d49b561 100644
--- a/src/test/java/org/apache/commons/lang3/math/NumberUtilsTest.java
+++ b/src/test/java/org/apache/commons/lang3/math/NumberUtilsTest.java
@@ -717,7 +717,7 @@ public class NumberUtilsTest {
         }
     }
 
-    private static void assertCreateNumberZero(String number, Object zero, Object negativeZero) {
+    private static void assertCreateNumberZero(final String number, final Object zero, final Object negativeZero) {
         assertEquals(zero, NumberUtils.createNumber(number), () -> "Input: " + number);
         assertEquals(zero, NumberUtils.createNumber("+" + number), () -> "Input: +" + number);
         assertEquals(negativeZero, NumberUtils.createNumber("-" + number), () -> "Input: -" + number);