diff --git a/jbpm/jbpm-bpmn2/src/main/java/org/jbpm/bpmn2/xml/AdHocSubProcessHandler.java b/jbpm/jbpm-bpmn2/src/main/java/org/jbpm/bpmn2/xml/AdHocSubProcessHandler.java
index 8d11bbc3dc5..89a24f95137 100755
--- a/jbpm/jbpm-bpmn2/src/main/java/org/jbpm/bpmn2/xml/AdHocSubProcessHandler.java
+++ b/jbpm/jbpm-bpmn2/src/main/java/org/jbpm/bpmn2/xml/AdHocSubProcessHandler.java
@@ -63,17 +63,26 @@ protected Node handleNode(final Node node, final Element element, final String u
         if ("false".equals(cancelRemainingInstances)) {
             dynamicNode.setCancelRemainingInstances(false);
         }
+
+        dynamicNode.setLanguage("http://www.java.com/java");
+
         // by default it should not autocomplete as it's adhoc
         org.w3c.dom.Node xmlNode = element.getFirstChild();
         dynamicNode.setActivationCondition((String) node.getMetaData().get(CUSTOM_ACTIVATION_CONDITION));
         while (xmlNode != null) {
             String nodeName = xmlNode.getNodeName();
             if (COMPLETION_CONDITION.equals(nodeName)) {
+                Element completeConditionElement = (Element) xmlNode;
+                String dialect = completeConditionElement.getAttribute("language");
+
                 String expression = xmlNode.getTextContent();
                 if (AUTOCOMPLETE_EXPRESSIONS.contains(expression)) {
                     dynamicNode.setAutoComplete(true);
                 } else {
                     dynamicNode.setCompletionCondition(expression);
+                    if (!dialect.isBlank()) {
+                        dynamicNode.setLanguage(dialect);
+                    }
                 }
             }
             xmlNode = xmlNode.getNextSibling();
@@ -104,7 +113,7 @@ public void writeNode(Node node, StringBuilder xmlDump, int metaDataType) {
         visitConnectionsAndAssociations(dynamicNode, xmlDump, metaDataType);
 
         if (dynamicNode.isAutoComplete()) {
-            xmlDump.append("    <completionCondition xsi:type=\"tFormalExpression\">" + AUTOCOMPLETE_COMPLETION_CONDITION + "</completionCondition>" + EOL);
+            xmlDump.append("<completionCondition xsi:type=\"tFormalExpression\" language=\"" + dynamicNode.getLanguage() + "\">" + AUTOCOMPLETE_COMPLETION_CONDITION + "</completionCondition>" + EOL);
         }
         endNode("adHocSubProcess", xmlDump);
     }
diff --git a/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/DynamicNodeVisitor.java b/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/DynamicNodeVisitor.java
index 6535aa5466f..555ac270adc 100644
--- a/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/DynamicNodeVisitor.java
+++ b/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/DynamicNodeVisitor.java
@@ -20,8 +20,10 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.stream.Stream;
 
+import org.jbpm.compiler.canonical.builtin.ReturnValueEvaluatorBuilderService;
 import org.jbpm.compiler.canonical.node.NodeVisitorBuilderService;
 import org.jbpm.process.core.context.variable.VariableScope;
 import org.jbpm.ruleflow.core.factory.DynamicNodeFactory;
@@ -35,8 +37,11 @@
 
 public class DynamicNodeVisitor extends CompositeContextNodeVisitor<DynamicNode> {
 
-    public DynamicNodeVisitor(NodeVisitorBuilderService nodeVisitorService) {
+    private ReturnValueEvaluatorBuilderService builder;
+
+    public DynamicNodeVisitor(NodeVisitorBuilderService nodeVisitorService, ClassLoader classLoader) {
         super(nodeVisitorService);
+        this.builder = ReturnValueEvaluatorBuilderService.instance(classLoader);
     }
 
     @Override
@@ -56,22 +61,26 @@ protected String getDefaultName() {
 
     @Override
     public Stream<MethodCallExpr> visitCustomFields(DynamicNode node, VariableScope variableScope) {
+        if (node.isAutoComplete()) {
+            return Collections.<MethodCallExpr> emptyList().stream();
+        }
+
         Collection<MethodCallExpr> methods = new ArrayList<>();
         methods.add(getFactoryMethod(getNodeId(node), METHOD_LANGUAGE, getOrNullExpr(node.getLanguage())));
-        if (node.getActivationCondition() != null && !node.getActivationCondition().trim().isEmpty()) {
-            methods.add(getActivationConditionStatement(node, variableScope));
+        if (node.getActivationCondition() != null && !node.getActivationCondition().isBlank()) {
+            methods.add(getActivationConditionStatement(node));
         }
-        if (node.getCompletionCondition() != null && !node.getCompletionCondition().trim().isEmpty()) {
-            methods.add(getCompletionConditionStatement(node, variableScope));
+        if (node.getCompletionCondition() != null && !node.getCompletionCondition().isBlank()) {
+            methods.add(getCompletionConditionStatement(node));
         }
         return methods.stream();
     }
 
-    private MethodCallExpr getActivationConditionStatement(DynamicNode node, VariableScope scope) {
-        return getFactoryMethod(getNodeId(node), METHOD_ACTIVATION_EXPRESSION, createLambdaExpr(node.getActivationCondition(), scope));
+    private MethodCallExpr getActivationConditionStatement(DynamicNode node) {
+        return getFactoryMethod(getNodeId(node), METHOD_ACTIVATION_EXPRESSION, builder.build(node, node.getLanguage(), node.getActivationCondition(), Boolean.class, (String) null));
     }
 
-    private MethodCallExpr getCompletionConditionStatement(DynamicNode node, VariableScope scope) {
-        return getFactoryMethod(getNodeId(node), METHOD_COMPLETION_EXPRESSION, createLambdaExpr(node.getCompletionCondition(), scope));
+    private MethodCallExpr getCompletionConditionStatement(DynamicNode node) {
+        return getFactoryMethod(getNodeId(node), METHOD_COMPLETION_EXPRESSION, builder.build(node, node.getLanguage(), node.getCompletionCondition(), Boolean.class, (String) null));
     }
 }
diff --git a/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/builtin/JavaConstraintEvaluatorBuilder.java b/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/builtin/JavaConstraintEvaluatorBuilder.java
index d85f3fe76ba..621592cc278 100644
--- a/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/builtin/JavaConstraintEvaluatorBuilder.java
+++ b/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/builtin/JavaConstraintEvaluatorBuilder.java
@@ -26,12 +26,14 @@
 import org.jbpm.process.core.context.variable.Variable;
 import org.jbpm.process.core.context.variable.VariableScope;
 
+import com.github.javaparser.ParseProblemException;
 import com.github.javaparser.StaticJavaParser;
 import com.github.javaparser.ast.body.Parameter;
 import com.github.javaparser.ast.expr.Expression;
 import com.github.javaparser.ast.expr.LambdaExpr;
 import com.github.javaparser.ast.expr.NameExpr;
 import com.github.javaparser.ast.stmt.BlockStmt;
+import com.github.javaparser.ast.stmt.ReturnStmt;
 import com.github.javaparser.ast.type.UnknownType;
 
 public class JavaConstraintEvaluatorBuilder implements ReturnValueEvaluatorBuilder {
@@ -48,7 +50,16 @@ public Expression build(ContextResolver resolver, String expression, Class<?> ty
                 new Parameter(new UnknownType(), KCONTEXT_VAR), // (kcontext) ->
                 actionBody);
 
-        BlockStmt blockStmt = StaticJavaParser.parseBlock("{" + expression + "}");
+        BlockStmt blockStmt = parseExpression(expression);
+
+        if (blockStmt == null) {
+            blockStmt = parseStatement(expression);
+        }
+
+        if (blockStmt == null) {
+            blockStmt = StaticJavaParser.parseBlock(expression);
+        }
+
         Set<NameExpr> identifiers = new HashSet<>(blockStmt.findAll(NameExpr.class));
 
         for (NameExpr v : identifiers) {
@@ -57,7 +68,7 @@ public Expression build(ContextResolver resolver, String expression, Class<?> ty
                 continue;
             }
             Variable variable = variableScope.findVariable(v.getNameAsString());
-            actionBody.addStatement(AbstractNodeVisitor.makeAssignment(variable));
+            actionBody.addStatement(0, AbstractNodeVisitor.makeAssignment(variable));
         }
 
         blockStmt.getStatements().forEach(actionBody::addStatement);
@@ -65,4 +76,23 @@ public Expression build(ContextResolver resolver, String expression, Class<?> ty
         return lambda;
     }
 
+    private BlockStmt parseStatement(String expression) {
+        try {
+            BlockStmt block = new BlockStmt();
+            block.addStatement(StaticJavaParser.parseStatement("{" + expression + "}"));
+            return block;
+        } catch (ParseProblemException e) {
+            return null;
+        }
+    }
+
+    private BlockStmt parseExpression(String expression) {
+        try {
+            BlockStmt block = new BlockStmt();
+            block.addStatement(new ReturnStmt(StaticJavaParser.parseExpression(expression)));
+            return block;
+        } catch (ParseProblemException e) {
+            return null;
+        }
+    }
 }
diff --git a/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/node/DynamicNodeVisitorBuilder.java b/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/node/DynamicNodeVisitorBuilder.java
index f463651f74a..fdf5f54821c 100644
--- a/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/node/DynamicNodeVisitorBuilder.java
+++ b/jbpm/jbpm-flow-builder/src/main/java/org/jbpm/compiler/canonical/node/DynamicNodeVisitorBuilder.java
@@ -32,7 +32,7 @@ public Class<?> type() {
 
     @Override
     public AbstractNodeVisitor<? extends Node> visitor(NodeVisitorBuilderService nodeVisitorService, ClassLoader classLoader) {
-        return new DynamicNodeVisitor(nodeVisitorService);
+        return new DynamicNodeVisitor(nodeVisitorService, classLoader);
     }
 
 }
diff --git a/jbpm/jbpm-flow/src/main/java/org/jbpm/ruleflow/core/factory/DynamicNodeFactory.java b/jbpm/jbpm-flow/src/main/java/org/jbpm/ruleflow/core/factory/DynamicNodeFactory.java
index 53acb5bcdcf..c956b051983 100755
--- a/jbpm/jbpm-flow/src/main/java/org/jbpm/ruleflow/core/factory/DynamicNodeFactory.java
+++ b/jbpm/jbpm-flow/src/main/java/org/jbpm/ruleflow/core/factory/DynamicNodeFactory.java
@@ -18,13 +18,11 @@
  */
 package org.jbpm.ruleflow.core.factory;
 
-import java.util.function.Predicate;
-
+import org.jbpm.process.instance.impl.ReturnValueEvaluator;
 import org.jbpm.ruleflow.core.RuleFlowNodeContainerFactory;
 import org.jbpm.workflow.core.NodeContainer;
 import org.jbpm.workflow.core.node.DynamicNode;
 import org.kie.api.definition.process.WorkflowElementIdentifier;
-import org.kie.api.runtime.process.ProcessContext;
 
 public class DynamicNodeFactory<T extends RuleFlowNodeContainerFactory<T, ?>> extends AbstractCompositeNodeFactory<DynamicNodeFactory<T>, T> {
 
@@ -45,12 +43,12 @@ public DynamicNodeFactory<T> language(String language) {
         return this;
     }
 
-    public DynamicNodeFactory<T> activationExpression(Predicate<ProcessContext> activationExpression) {
+    public DynamicNodeFactory<T> activationExpression(ReturnValueEvaluator activationExpression) {
         getDynamicNode().setActivationExpression(activationExpression);
         return this;
     }
 
-    public DynamicNodeFactory<T> completionExpression(Predicate<ProcessContext> completionExpression) {
+    public DynamicNodeFactory<T> completionExpression(ReturnValueEvaluator completionExpression) {
         getDynamicNode().setCompletionExpression(completionExpression);
         return this;
     }
diff --git a/jbpm/jbpm-flow/src/main/java/org/jbpm/workflow/core/node/DynamicNode.java b/jbpm/jbpm-flow/src/main/java/org/jbpm/workflow/core/node/DynamicNode.java
index d09348f1e5f..5130acaddc2 100755
--- a/jbpm/jbpm-flow/src/main/java/org/jbpm/workflow/core/node/DynamicNode.java
+++ b/jbpm/jbpm-flow/src/main/java/org/jbpm/workflow/core/node/DynamicNode.java
@@ -20,9 +20,9 @@
 
 import java.util.Arrays;
 import java.util.List;
-import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
+import org.jbpm.process.instance.impl.ReturnValueEvaluator;
 import org.kie.api.definition.process.Node;
 import org.kie.api.definition.process.WorkflowElementIdentifier;
 import org.kie.api.runtime.process.ProcessContext;
@@ -42,8 +42,8 @@ public class DynamicNode extends CompositeContextNode {
      */
     private String completionCondition;
 
-    private Predicate<ProcessContext> activationPredicate;
-    private Predicate<ProcessContext> completionPredicate;
+    private ReturnValueEvaluator activationPredicate;
+    private ReturnValueEvaluator completionPredicate;
     private String language;
 
     public DynamicNode() {
@@ -89,22 +89,22 @@ public void setCompletionCondition(String completionCondition) {
         this.completionCondition = completionCondition;
     }
 
-    public DynamicNode setActivationExpression(Predicate<ProcessContext> activationPredicate) {
+    public DynamicNode setActivationExpression(ReturnValueEvaluator activationPredicate) {
         this.activationPredicate = activationPredicate;
         return this;
     }
 
-    public DynamicNode setCompletionExpression(Predicate<ProcessContext> copmletionPredicate) {
+    public DynamicNode setCompletionExpression(ReturnValueEvaluator copmletionPredicate) {
         this.completionPredicate = copmletionPredicate;
         return this;
     }
 
     public boolean canActivate(ProcessContext context) {
-        return activationPredicate == null || activationPredicate.test(context);
+        return activationPredicate == null || (Boolean) activationPredicate.eval(context);
     }
 
     public boolean canComplete(ProcessContext context) {
-        return isAutoComplete() || (completionPredicate != null && completionPredicate.test(context));
+        return isAutoComplete() || (completionPredicate != null && (Boolean) completionPredicate.eval(context));
     }
 
     public boolean hasCompletionCondition() {