diff --git a/grails-controllers/src/main/groovy/org/grails/compiler/web/ControllerActionTransformer.java b/grails-controllers/src/main/groovy/org/grails/compiler/web/ControllerActionTransformer.java
index fa03fc2f79b..7ab580e96a1 100644
--- a/grails-controllers/src/main/groovy/org/grails/compiler/web/ControllerActionTransformer.java
+++ b/grails-controllers/src/main/groovy/org/grails/compiler/web/ControllerActionTransformer.java
@@ -112,9 +112,7 @@
 import static org.codehaus.groovy.ast.tools.GeneralUtils.declX;
 import static org.codehaus.groovy.ast.tools.GeneralUtils.ifS;
 import static org.codehaus.groovy.ast.tools.GeneralUtils.localVarX;
-import static org.codehaus.groovy.ast.tools.GeneralUtils.nullX;
 import static org.codehaus.groovy.ast.tools.GeneralUtils.stmt;
-import static org.codehaus.groovy.ast.tools.GeneralUtils.ternaryX;
 import static org.codehaus.groovy.ast.tools.GeneralUtils.varX;
 import static org.grails.compiler.injection.GrailsASTUtils.applyDefaultMethodTarget;
 import static org.grails.compiler.injection.GrailsASTUtils.applyMethodTarget;
@@ -888,11 +886,17 @@ protected void initializeStringParameter(final ClassNode classNode, final BlockS
 
         final ClassNode paramTypeClassNode = param.getType();
         final String methodParamName = param.getName();
-        Expression getParamsExpression = buildGetPropertyExpression(localVarX("this", classNode), "params", classNode);
-        final BooleanExpression containsKeyExpression = boolX(applyDefaultMethodTarget(callX(getParamsExpression, "containsKey", args(constX(requestParameterName))), Map.class));
-
-        wrapper.addStatement(stmt(declX(localVarX(methodParamName, paramTypeClassNode),
-                ternaryX(containsKeyExpression, buildGetMapExpression(getParamsExpression, requestParameterName), nullX()))));
+        Expression getParamsExpression = buildGetPropertyExpression(new VariableExpression("this"), "params", classNode);
+        final Expression paramsContainsKeyMethodArguments = new ArgumentListExpression(
+                new ConstantExpression(requestParameterName));
+        final BooleanExpression containsKeyExpression = new BooleanExpression(
+                applyDefaultMethodTarget(new MethodCallExpression(getParamsExpression, "containsKey", paramsContainsKeyMethodArguments), Map.class));
+        final Statement initializeParameterStatement = new ExpressionStatement(
+                new DeclarationExpression(new VariableExpression(
+                        methodParamName, paramTypeClassNode),
+                        Token.newSymbol(Types.EQUALS, 0, 0),
+                        new TernaryExpression(containsKeyExpression, buildGetMapExpression(getParamsExpression, requestParameterName), new ConstantExpression(null))));
+        wrapper.addStatement(initializeParameterStatement);
     }
 
     protected void initializePrimitiveOrTypeWrapperParameter(final ClassNode classNode, final BlockStatement wrapper,
diff --git a/grails-test-examples/app1/src/integration-test/groovy/functionaltests/commandobjects/CommandObjectSpec.groovy b/grails-test-examples/app1/src/integration-test/groovy/functionaltests/commandobjects/CommandObjectSpec.groovy
index a7211c638b6..125ac655b88 100644
--- a/grails-test-examples/app1/src/integration-test/groovy/functionaltests/commandobjects/CommandObjectSpec.groovy
+++ b/grails-test-examples/app1/src/integration-test/groovy/functionaltests/commandobjects/CommandObjectSpec.groovy
@@ -22,11 +22,13 @@ package functionaltests.commandobjects
 import grails.plugin.geb.ContainerGebSpec
 import grails.testing.mixin.integration.Integration
 import spock.lang.Issue
+import spock.lang.PendingFeature
 
 @Integration
 @Issue('https://github.com/apache/grails-core/issues/14947')
 class CommandObjectSpec extends ContainerGebSpec {
 
+    @PendingFeature
     void 'should display the correct title on the home page'() {
         when: 'visiting the home page'
         go('/commandObject/echo?person=George+Doe')