diff --git a/src/main/java/de/neemann/digital/draw/library/ElementTypeDescriptionCustom.java b/src/main/java/de/neemann/digital/draw/library/ElementTypeDescriptionCustom.java
index 8108a5214..4d7199698 100644
--- a/src/main/java/de/neemann/digital/draw/library/ElementTypeDescriptionCustom.java
+++ b/src/main/java/de/neemann/digital/draw/library/ElementTypeDescriptionCustom.java
@@ -25,7 +25,6 @@ import de.neemann.digital.lang.Lang;
 
 import java.io.File;
 import java.io.IOException;
-import java.util.HashMap;
 import java.util.TreeSet;
 
 /**
@@ -36,7 +35,7 @@ public final class ElementTypeDescriptionCustom extends ElementTypeDescription {
     private static final int MAX_DEPTH = 30;
     private final File file;
     private final Circuit circuit;
-    private final HashMap<String, Statement> map;
+    private final StatementCache statementCache;
     private String description;
     private NetList netList;
     private boolean isCustom = true;
@@ -53,7 +52,7 @@ public final class ElementTypeDescriptionCustom extends ElementTypeDescription {
         super(file.getName(), (ElementFactory) null, circuit.getInputNames());
         this.file = file;
         this.circuit = circuit;
-        map = new HashMap<>();
+        statementCache=new StatementCache();
         setShortName(file.getName());
         addAttribute(Keys.ROTATE);
         addAttribute(Keys.LABEL);
@@ -130,10 +129,8 @@ public final class ElementTypeDescriptionCustom extends ElementTypeDescription {
                 if (args == null) {
                     String argsCode = containingVisualElement.getElementAttributes().get(Keys.GENERIC);
                     try {
-                        Statement s = getStatement(argsCode);
+                        Statement s = statementCache.getStatement(argsCode);
                         args = new Context();
-                        if (containingVisualElement.getGenericArgs() != null)
-                            args.declareVar("args", containingVisualElement.getGenericArgs());
                         s.execute(args);
                     } catch (HGSEvalException | ParserException | IOException e) {
                         final NodeException ex = new NodeException(Lang.get("err_evaluatingGenericsCode_N_N", containingVisualElement, argsCode), e);
@@ -150,7 +147,7 @@ public final class ElementTypeDescriptionCustom extends ElementTypeDescription {
                 try {
                     if (!gen.isEmpty()) {
                         boolean isCustom = library.getElementType(ve.getElementName(), ve.getElementAttributes()).isCustom();
-                        Statement genS = getStatement(gen);
+                        Statement genS = statementCache.getStatement(gen);
                         if (isCustom) {
                             Context mod = new Context()
                                     .declareVar("args", args)
@@ -182,15 +179,6 @@ public final class ElementTypeDescriptionCustom extends ElementTypeDescription {
             return new ModelCreator(circuit, library, true, new NetList(netList, errorVisualElement), subName, depth, errorVisualElement);
     }
 
-    private Statement getStatement(String code) throws IOException, ParserException {
-        Statement genS = map.get(code);
-        if (genS == null) {
-            genS = new Parser(code).parse(false);
-            map.put(code, genS);
-        }
-        return genS;
-    }
-
     @Override
     public boolean isCustom() {
         return isCustom;
diff --git a/src/main/java/de/neemann/digital/draw/library/StatementCache.java b/src/main/java/de/neemann/digital/draw/library/StatementCache.java
new file mode 100644
index 000000000..6a705729e
--- /dev/null
+++ b/src/main/java/de/neemann/digital/draw/library/StatementCache.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2019 Helmut Neemann.
+ * Use of this source code is governed by the GPL v3 license
+ * that can be found in the LICENSE file.
+ */
+package de.neemann.digital.draw.library;
+
+import de.neemann.digital.hdl.hgs.Parser;
+import de.neemann.digital.hdl.hgs.ParserException;
+import de.neemann.digital.hdl.hgs.Statement;
+
+import java.io.IOException;
+import java.util.HashMap;
+
+/**
+ * Implements a cache for statements
+ */
+public class StatementCache {
+    private final HashMap<String, Statement> map;
+
+    /**
+     * Creates a new instance
+     */
+    public StatementCache() {
+        map = new HashMap<>();
+    }
+
+    /**
+     * Gets the analysed statements.
+     * If the statements are not present in the cache, they are generated.
+     *
+     * @param code the code
+     * @return the statements
+     * @throws IOException     IOException
+     * @throws ParserException ParserException
+     */
+    public Statement getStatement(String code) throws IOException, ParserException {
+        Statement genS = map.get(code);
+        if (genS == null) {
+            genS = new Parser(code).parse(false);
+            map.put(code, genS);
+        }
+        return genS;
+    }
+
+}