diff --git a/src/main/java/org/apache/commons/lang3/time/StopWatch.java b/src/main/java/org/apache/commons/lang3/time/StopWatch.java
index 1552ceae0e5..6164c993206 100644
--- a/src/main/java/org/apache/commons/lang3/time/StopWatch.java
+++ b/src/main/java/org/apache/commons/lang3/time/StopWatch.java
@@ -170,7 +170,7 @@ boolean isSuspended() {
         abstract boolean isSuspended();
     }
 
-    private static final long NANO_2_MILLIS = 1000000L;
+    private static final long NANO_2_MILLIS = 1_000_000L;
 
     /**
      * Creates a StopWatch.