diff --git a/src/main/javassist/bytecode/StackMapTable.java b/src/main/javassist/bytecode/StackMapTable.java
index 62a6aca0..4fed2010 100644
--- a/src/main/javassist/bytecode/StackMapTable.java
+++ b/src/main/javassist/bytecode/StackMapTable.java
@@ -912,9 +912,15 @@ else if (offsetDelta < 64 && current != entry) {
         static byte[] insertGap(byte[] info, int where, int gap) {
             int len = info.length;
             byte[] newinfo = new byte[len + gap];
-            for (int i = 0; i < len; i++)
-                newinfo[i + (i < where ? 0 : gap)] = info[i];
-
+            if (where <= 0) {
+                System.arraycopy(info, 0, newinfo, gap, len);
+            } else if (where >= len) {
+                System.arraycopy(info, 0, newinfo, 0, len);
+            } else {
+                assert (where > 0 && where < len);
+                System.arraycopy(info, 0, newinfo, 0, where);
+                System.arraycopy(info, where, newinfo, where + gap, len - where);
+            }
             return newinfo;
         }
 
diff --git a/src/main/javassist/bytecode/stackmap/MapMaker.java b/src/main/javassist/bytecode/stackmap/MapMaker.java
index bd79377f..d016a3be 100644
--- a/src/main/javassist/bytecode/stackmap/MapMaker.java
+++ b/src/main/javassist/bytecode/stackmap/MapMaker.java
@@ -309,8 +309,7 @@ protected static int recordTypeData(int n, TypeData[] srcTypes, TypeData[] destT
     }
 
     protected static void copyTypeData(int n, TypeData[] srcTypes, TypeData[] destTypes) {
-        for (int i = 0; i < n; i++)
-            destTypes[i] = srcTypes[i];
+        System.arraycopy(srcTypes, 0, destTypes, 0, n);
     }
 
     private static TypeData validateTypeData(TypeData[] data, int length, int index) {