diff --git a/release-notes/VERSION b/release-notes/VERSION
index 1d41330aa6..69679e274c 100644
--- a/release-notes/VERSION
+++ b/release-notes/VERSION
@@ -17,6 +17,8 @@ JSON library.
 2.5.5 (not yet released)
 
 #220: Problem with `JsonParser.nextFieldName(SerializableString)` for byte-backed parser
+#221: Fixed ArrayIndexOutOfBounds exception for character-based `JsonGenerator`
+ (reported by a-lerion@github)
 
 2.5.4 (09-Jun-2015)
 
diff --git a/src/main/java/com/fasterxml/jackson/core/json/UTF8JsonGenerator.java b/src/main/java/com/fasterxml/jackson/core/json/UTF8JsonGenerator.java
index 6eba628e0e..6f34187222 100644
--- a/src/main/java/com/fasterxml/jackson/core/json/UTF8JsonGenerator.java
+++ b/src/main/java/com/fasterxml/jackson/core/json/UTF8JsonGenerator.java
@@ -5,7 +5,6 @@
 import java.math.BigInteger;
 
 import com.fasterxml.jackson.core.*;
-import com.fasterxml.jackson.core.JsonGenerator.Feature;
 import com.fasterxml.jackson.core.io.*;
 
 public class UTF8JsonGenerator
diff --git a/src/main/java/com/fasterxml/jackson/core/json/WriterBasedJsonGenerator.java b/src/main/java/com/fasterxml/jackson/core/json/WriterBasedJsonGenerator.java
index 25519972a3..0e8b6c596f 100644
--- a/src/main/java/com/fasterxml/jackson/core/json/WriterBasedJsonGenerator.java
+++ b/src/main/java/com/fasterxml/jackson/core/json/WriterBasedJsonGenerator.java
@@ -1813,7 +1813,7 @@ private void _appendCharacterEscape(char ch, int escCode)
             return;
         }
         if (escCode != CharacterEscapes.ESCAPE_CUSTOM) { // std, \\uXXXX
-            if ((_outputTail + 2) > _outputEnd) {
+            if ((_outputTail + 5) >= _outputEnd) {
                 _flushBuffer();
             }
             int ptr = _outputTail;