diff --git a/modules/lang-painless/src/main/java/org/elasticsearch/painless/WriterConstants.java b/modules/lang-painless/src/main/java/org/elasticsearch/painless/WriterConstants.java
index 98aee5b7d90..86111d8f1a5 100644
--- a/modules/lang-painless/src/main/java/org/elasticsearch/painless/WriterConstants.java
+++ b/modules/lang-painless/src/main/java/org/elasticsearch/painless/WriterConstants.java
@@ -37,9 +37,10 @@ import java.util.Map;
 public final class WriterConstants {
 
     public final static String BASE_CLASS_NAME = Executable.class.getName();
-    public final static String CLASS_NAME      = BASE_CLASS_NAME + "$Script";
     public final static Type BASE_CLASS_TYPE   = Type.getType(Executable.class);
-    public final static Type CLASS_TYPE        = Type.getType("L" + CLASS_NAME.replace(".", "/") + ";");
+    
+    public final static String CLASS_NAME      = BASE_CLASS_NAME + "$Script";
+    public final static Type CLASS_TYPE        = Type.getObjectType(CLASS_NAME.replace('.', '/'));
 
     public final static Method CONSTRUCTOR = getAsmMethod(void.class, "<init>", String.class, String.class);
     public final static Method EXECUTE     =
diff --git a/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefArray.java b/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefArray.java
index 41eac59e4ff..38e8bf89cc9 100644
--- a/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefArray.java
+++ b/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefArray.java
@@ -61,15 +61,13 @@ final class LDefArray extends ALink {
     @Override
     void load(final CompilerSettings settings, final Definition definition, final GeneratorAdapter adapter) {
         final String desc = Type.getMethodDescriptor(after.type, definition.defType.type, index.actual.type);
-        adapter.visitInvokeDynamicInsn(
-            "arrayLoad", desc, DEF_BOOTSTRAP_HANDLE, new Object[] { DefBootstrap.ARRAY_LOAD });
+        adapter.visitInvokeDynamicInsn("arrayLoad", desc, DEF_BOOTSTRAP_HANDLE, DefBootstrap.ARRAY_LOAD);
     }
 
     @Override
     void store(final CompilerSettings settings, final Definition definition, final GeneratorAdapter adapter) {
         final String desc = Type.getMethodDescriptor(definition.voidType.type, definition.defType.type,
             index.actual.type, definition.defType.type);
-        adapter.visitInvokeDynamicInsn(
-            "arrayStore", desc, DEF_BOOTSTRAP_HANDLE, new Object[] { DefBootstrap.ARRAY_STORE });
+        adapter.visitInvokeDynamicInsn("arrayStore", desc, DEF_BOOTSTRAP_HANDLE, DefBootstrap.ARRAY_STORE);
     }
 }
diff --git a/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefCall.java b/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefCall.java
index eef3c835e45..2bf53bcf89b 100644
--- a/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefCall.java
+++ b/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefCall.java
@@ -84,7 +84,7 @@ final class LDefCall extends ALink {
         // return value
         signature.append(after.type.getDescriptor());
 
-        adapter.visitInvokeDynamicInsn(name, signature.toString(), DEF_BOOTSTRAP_HANDLE, new Object[] { DefBootstrap.METHOD_CALL });
+        adapter.visitInvokeDynamicInsn(name, signature.toString(), DEF_BOOTSTRAP_HANDLE, DefBootstrap.METHOD_CALL);
     }
 
     @Override
diff --git a/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefField.java b/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefField.java
index cb1c37a7b01..68fb7ffb95a 100644
--- a/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefField.java
+++ b/modules/lang-painless/src/main/java/org/elasticsearch/painless/node/LDefField.java
@@ -57,12 +57,12 @@ final class LDefField extends ALink {
     @Override
     void load(final CompilerSettings settings, final Definition definition, final GeneratorAdapter adapter) {
         final String desc = Type.getMethodDescriptor(after.type, definition.defType.type);
-        adapter.visitInvokeDynamicInsn(value, desc, DEF_BOOTSTRAP_HANDLE, new Object[] { DefBootstrap.LOAD });
+        adapter.visitInvokeDynamicInsn(value, desc, DEF_BOOTSTRAP_HANDLE, DefBootstrap.LOAD);
     }
 
     @Override
     void store(final CompilerSettings settings, final Definition definition, final GeneratorAdapter adapter) {
         final String desc = Type.getMethodDescriptor(definition.voidType.type, definition.defType.type, definition.defType.type);
-        adapter.visitInvokeDynamicInsn(value, desc, DEF_BOOTSTRAP_HANDLE, new Object[] { DefBootstrap.STORE });
+        adapter.visitInvokeDynamicInsn(value, desc, DEF_BOOTSTRAP_HANDLE, DefBootstrap.STORE);
     }
 }