diff --git a/src/main/java/org/apache/maven/shared/archiver/MavenArchiver.java b/src/main/java/org/apache/maven/shared/archiver/MavenArchiver.java
index 7ab7740..cbab812 100644
--- a/src/main/java/org/apache/maven/shared/archiver/MavenArchiver.java
+++ b/src/main/java/org/apache/maven/shared/archiver/MavenArchiver.java
@@ -717,7 +717,7 @@ private static boolean isNumeric(String str) {
         }
 
         for (char c : str.toCharArray()) {
-            if (!Character.isDigit(c)) {
+            if (c < '0' || c > '9') {
                 return false;
             }
         }
diff --git a/src/test/java/org/apache/maven/shared/archiver/MavenArchiverTest.java b/src/test/java/org/apache/maven/shared/archiver/MavenArchiverTest.java
index 2419bda..e27b76e 100644
--- a/src/test/java/org/apache/maven/shared/archiver/MavenArchiverTest.java
+++ b/src/test/java/org/apache/maven/shared/archiver/MavenArchiverTest.java
@@ -1314,6 +1314,26 @@ void thrownParseOutputTimestampInstant(String outputTimestamp) {
                 .withCauseInstanceOf(DateTimeParseException.class);
     }
 
+    @ParameterizedTest
+    @ValueSource(
+            strings = {
+                // Arabic-Indic digits (U+0660–U+0669)
+                "٠١٢٣٤٥٦٧٨٩",
+                // Bengali digits (U+09E6–U+09EF)
+                "০১২৩৪",
+                // Devanagari digits (U+0966–U+096F)
+                "०१२३४",
+                // Extended Arabic-Indic digits (U+06F0–U+06F9)
+                "۰۱۲۳۴"
+            })
+    void unicodeDigitsAreRejectedAsTimestamp(String unicodeDigits) {
+        // Character.isDigit() returns true for non-ASCII digits, but Long.parseLong() only accepts ASCII 0-9.
+        // These must not throw NumberFormatException — they must yield IAE with DateTimeParseException cause.
+        assertThatExceptionOfType(IllegalArgumentException.class)
+                .isThrownBy(() -> MavenArchiver.parseBuildOutputTimestamp(unicodeDigits))
+                .withCauseInstanceOf(DateTimeParseException.class);
+    }
+
     @ParameterizedTest
     @CsvSource({
         "2011-12-03T10:15:30+01,1322903730",