diff --git a/api/all/src/main/java/io/opentelemetry/api/internal/OtelEncodingUtils.java b/api/all/src/main/java/io/opentelemetry/api/internal/OtelEncodingUtils.java
index 19fa277b377..2b062a12bd3 100644
--- a/api/all/src/main/java/io/opentelemetry/api/internal/OtelEncodingUtils.java
+++ b/api/all/src/main/java/io/opentelemetry/api/internal/OtelEncodingUtils.java
@@ -43,7 +43,7 @@ private static byte[] buildDecodingArray() {
   }
 
   private static boolean[] buildValidHexArray() {
-    boolean[] validHex = new boolean[Character.MAX_VALUE];
+    boolean[] validHex = new boolean[Character.MAX_VALUE + 1];
     // Use the fact that the default initial boolean value is false
     // and only explicitly init the values between the extreme HEX values
     // This minimized impact during process startup esp. on mobile.