diff --git a/src/main/java/org/apache/commons/validator/routines/BigIntegerValidator.java b/src/main/java/org/apache/commons/validator/routines/BigIntegerValidator.java
index 27c44735f..8dc6a6a95 100644
--- a/src/main/java/org/apache/commons/validator/routines/BigIntegerValidator.java
+++ b/src/main/java/org/apache/commons/validator/routines/BigIntegerValidator.java
@@ -16,6 +16,7 @@
  */
 package org.apache.commons.validator.routines;
 
+import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.text.Format;
 import java.text.NumberFormat;
@@ -157,7 +158,10 @@ public boolean minValue(final BigInteger value, final long min) {
      */
     @Override
     protected Object processParsedValue(final Object value, final Format formatter) {
-        return BigInteger.valueOf(((Number) value).longValue());
+        if (value instanceof Long) {
+            return BigInteger.valueOf(((Long) value).longValue());
+        }
+        return new BigDecimal(value.toString()).toBigInteger();
     }
 
     /**
diff --git a/src/test/java/org/apache/commons/validator/routines/BigIntegerValidatorTest.java b/src/test/java/org/apache/commons/validator/routines/BigIntegerValidatorTest.java
index 8c2416d12..482b6e85d 100644
--- a/src/test/java/org/apache/commons/validator/routines/BigIntegerValidatorTest.java
+++ b/src/test/java/org/apache/commons/validator/routines/BigIntegerValidatorTest.java
@@ -134,4 +134,21 @@ void testBigIntegerValidatorMethods() {
         assertFalse(BigIntegerValidator.getInstance().isValid(xxxx, pattern), "isValid(B) pattern");
         assertFalse(BigIntegerValidator.getInstance().isValid(patternVal, pattern, Locale.GERMAN), "isValid(B) both");
     }
+
+    /**
+     * Test a value larger than {@link Long#MAX_VALUE} keeps its magnitude instead of being
+     * clamped to {@link Long#MAX_VALUE}.
+     */
+    @Test
+    void testBigIntegerAboveLongMaxValue() {
+        // One past Long.MAX_VALUE, so NumberFormat parses it as a Double rather than a Long.
+        final BigInteger aboveLong = BigInteger.valueOf(Long.MAX_VALUE).add(BigInteger.ONE);
+        final String input = aboveLong.toString();
+        final BigInteger result = BigIntegerValidator.getInstance().validate(input, "#");
+        assertTrue(result.compareTo(BigInteger.valueOf(Long.MAX_VALUE)) > 0, "value clamped to Long.MAX_VALUE");
+        assertFalse(BigIntegerValidator.getInstance().maxValue(result, Long.MAX_VALUE), "maxValue should fail for values > Long.MAX_VALUE");
+        assertFalse(BigIntegerValidator.getInstance().isInRange(result, Long.MIN_VALUE, Long.MAX_VALUE), "isInRange should fail for values > Long.MAX_VALUE");
+        // BigDecimalValidator already preserves the magnitude, so the two must agree
+        assertEquals(BigDecimalValidator.getInstance().validate(input, "#").toBigInteger(), result);
+    }
 }