diff --git a/src/main/java/org/apache/commons/text/StringSubstitutor.java b/src/main/java/org/apache/commons/text/StringSubstitutor.java
index f4b53eec17..01fc5510d5 100644
--- a/src/main/java/org/apache/commons/text/StringSubstitutor.java
+++ b/src/main/java/org/apache/commons/text/StringSubstitutor.java
@@ -1408,7 +1408,7 @@ private int substitute(final TextStringBuilder buf, final int offset, final int
                                 // on the first call initialize priorVariables
                                 if (priorVariables == null) {
                                     priorVariables = new ArrayList<>();
-                                    priorVariables.add(new String(chars, offset, length));
+                                    priorVariables.add(new String(chars, offset, length + lengthChange));
                                 }
 
                                 // handle cyclic substitution
diff --git a/src/test/java/org/apache/commons/text/StringSubstitutorTest.java b/src/test/java/org/apache/commons/text/StringSubstitutorTest.java
index b4390d808b..3705cea3a9 100644
--- a/src/test/java/org/apache/commons/text/StringSubstitutorTest.java
+++ b/src/test/java/org/apache/commons/text/StringSubstitutorTest.java
@@ -23,6 +23,7 @@
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.HashMap;
@@ -541,6 +542,30 @@ public void testReplaceToIdentical() {
         doTestReplace("The ${animal} jumps.", "The ${animal} jumps.", true);
     }
 
+    /**
+     * Tests a cyclic replace operation.
+     * The cycle should be detected and cause an exception to be thrown.
+     */
+    @Test
+    public void testCyclicReplacement() {
+        final Map<String, String> map = new HashMap<>();
+        map.put("animal", "${critter}");
+        map.put("target", "${pet}");
+        map.put("pet", "${petCharacteristic} dog");
+        map.put("petCharacteristic", "lazy");
+        map.put("critter", "${critterSpeed} ${critterColor} ${critterType}");
+        map.put("critterSpeed", "quick");
+        map.put("critterColor", "brown");
+        map.put("critterType", "${animal}");
+        final StringSubstitutor sub = new StringSubstitutor(map);
+        assertThrows(IllegalStateException.class, () -> sub.replace("The ${animal} jumps over the ${target}."));
+
+        // also check even when default value is set.
+        map.put("critterType", "${animal:-fox}");
+        assertThrows(IllegalStateException.class,
+                () -> new StringSubstitutor(map).replace("The ${animal} jumps over the ${target}."));
+    }
+
     /**
      * Tests unknown key replace.
      */