diff --git a/src/main/java/org/apache/commons/collections4/trie/analyzer/StringKeyAnalyzer.java b/src/main/java/org/apache/commons/collections4/trie/analyzer/StringKeyAnalyzer.java
index 9552e5a5c8..4f63821ddf 100644
--- a/src/main/java/org/apache/commons/collections4/trie/analyzer/StringKeyAnalyzer.java
+++ b/src/main/java/org/apache/commons/collections4/trie/analyzer/StringKeyAnalyzer.java
@@ -82,6 +82,9 @@ public int bitIndex(final String key, final int offsetInBits, final int lengthIn
                 k = 0;
             } else {
                 k = key.charAt(index1);
+                if (k == 0) {
+                    throw new IllegalArgumentException("Character '\\u0000' is not supported in the key.");
+                }
             }
 
             if (other == null || index2 >= endIndex2) {
diff --git a/src/test/java/org/apache/commons/collections4/trie/PatriciaTrieTest.java b/src/test/java/org/apache/commons/collections4/trie/PatriciaTrieTest.java
index 04cb3add70..7dd4032e12 100755
--- a/src/test/java/org/apache/commons/collections4/trie/PatriciaTrieTest.java
+++ b/src/test/java/org/apache/commons/collections4/trie/PatriciaTrieTest.java
@@ -19,6 +19,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.ConcurrentModificationException;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
@@ -427,6 +428,24 @@ public void testPrefixMapClearUsingRemove() {
         assertEquals(Arrays.asList(2, 3, 7, 1), new ArrayList<>(trie.values()));
     }
 
+    public void testNullTerminatedKey() {
+        // COLLECTIONS-714
+        PatriciaTrie<Integer> trie = new PatriciaTrie<>();
+        try {
+            trie.put("x\u0000", 1);
+        } catch (IllegalArgumentException e) {
+            // expected
+        }
+
+        Map<String, Integer> map = new HashMap<>();
+        map.put("x\u0000", 1);
+        try {
+            trie = new PatriciaTrie<>(map);
+        } catch (IllegalArgumentException e) {
+            // expected
+        }
+    }
+
     //-----------------------------------------------------------------------
 
     @Override