diff --git a/src/main/java/org/apache/commons/validator/routines/checkdigit/CASNumberCheckDigit.java b/src/main/java/org/apache/commons/validator/routines/checkdigit/CASNumberCheckDigit.java
index 4139ab890..db740f94c 100644
--- a/src/main/java/org/apache/commons/validator/routines/checkdigit/CASNumberCheckDigit.java
+++ b/src/main/java/org/apache/commons/validator/routines/checkdigit/CASNumberCheckDigit.java
@@ -110,9 +110,10 @@ public boolean isValid(final String code) {
         if (!(cde instanceof String)) {
             return false;
         }
+        final String validated = (String) cde;
         try {
-            final int modulusResult = INSTANCE.calculateModulus((String) cde, true);
-            return modulusResult == Character.getNumericValue(code.charAt(code.length() - 1));
+            final int modulusResult = INSTANCE.calculateModulus(validated, true);
+            return modulusResult == Character.getNumericValue(validated.charAt(validated.length() - 1));
         } catch (final CheckDigitException ex) {
             return false;
         }
diff --git a/src/main/java/org/apache/commons/validator/routines/checkdigit/ECNumberCheckDigit.java b/src/main/java/org/apache/commons/validator/routines/checkdigit/ECNumberCheckDigit.java
index 50f6d11a3..7b73d2fdc 100644
--- a/src/main/java/org/apache/commons/validator/routines/checkdigit/ECNumberCheckDigit.java
+++ b/src/main/java/org/apache/commons/validator/routines/checkdigit/ECNumberCheckDigit.java
@@ -98,9 +98,10 @@ public boolean isValid(final String code) {
         if (!(cde instanceof String)) {
             return false;
         }
+        final String validated = (String) cde;
         try {
-            final int modulusResult = INSTANCE.calculateModulus((String) cde, true);
-            return modulusResult == Character.getNumericValue(code.charAt(code.length() - 1));
+            final int modulusResult = INSTANCE.calculateModulus(validated, true);
+            return modulusResult == Character.getNumericValue(validated.charAt(validated.length() - 1));
         } catch (final CheckDigitException ex) {
             return false;
         }
diff --git a/src/test/java/org/apache/commons/validator/routines/checkdigit/CASNumberCheckDigitTest.java b/src/test/java/org/apache/commons/validator/routines/checkdigit/CASNumberCheckDigitTest.java
index f36e77685..940a154d5 100644
--- a/src/test/java/org/apache/commons/validator/routines/checkdigit/CASNumberCheckDigitTest.java
+++ b/src/test/java/org/apache/commons/validator/routines/checkdigit/CASNumberCheckDigitTest.java
@@ -16,7 +16,10 @@
  */
 package org.apache.commons.validator.routines.checkdigit;
 
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 /**
  * CAS Number Check Digit Tests.
@@ -55,4 +58,13 @@ protected void setUp() {
         valid = new String[] {MIN, WATER, ETHANOL, ASPIRIN, COFFEIN, FORMALDEHYDE, DEXAMETHASONE, ARSENIC, ASBESTOS, MAX};
     }
 
+    /**
+     * The format validator trims the input, so surrounding whitespace must not change the result.
+     */
+    @Test
+    void testIsValidSurroundingWhitespace() {
+        assertTrue(routine.isValid(" " + WATER), "leading whitespace");
+        assertTrue(routine.isValid(WATER + " "), "trailing whitespace");
+    }
+
 }
diff --git a/src/test/java/org/apache/commons/validator/routines/checkdigit/ECNumberCheckDigitTest.java b/src/test/java/org/apache/commons/validator/routines/checkdigit/ECNumberCheckDigitTest.java
index 89a8a4ee7..7d3ba8654 100644
--- a/src/test/java/org/apache/commons/validator/routines/checkdigit/ECNumberCheckDigitTest.java
+++ b/src/test/java/org/apache/commons/validator/routines/checkdigit/ECNumberCheckDigitTest.java
@@ -16,7 +16,10 @@
  */
 package org.apache.commons.validator.routines.checkdigit;
 
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 /**
  * EC Number Check Digit Tests.
@@ -51,4 +54,13 @@ protected void setUp() {
         valid = new String[] {MIN, FORMALDEHYDE, DEXAMETHASONE, ARSENIC, ASBESTOS, MAX};
     }
 
+    /**
+     * The format validator trims the input, so surrounding whitespace must not change the result.
+     */
+    @Test
+    void testIsValidSurroundingWhitespace() {
+        assertTrue(routine.isValid(" " + DEXAMETHASONE), "leading whitespace");
+        assertTrue(routine.isValid(DEXAMETHASONE + " "), "trailing whitespace");
+    }
+
 }