diff --git a/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddablePart.groovy b/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddablePart.groovy
index e23c77a..c54dcb7 100644
--- a/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddablePart.groovy
+++ b/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddablePart.groovy
@@ -3,9 +3,12 @@ package com.jessebrault.ssg.dsl
 import com.jessebrault.ssg.part.Part
 import com.jessebrault.ssg.render.RenderContext
 import com.jessebrault.ssg.text.Text
+import com.jessebrault.ssg.util.Diagnostic
 import groovy.transform.EqualsAndHashCode
 import org.jetbrains.annotations.Nullable
 
+import java.util.function.Consumer
+
 import static java.util.Objects.requireNonNull
 
 @EqualsAndHashCode(includeFields = true)
@@ -13,7 +16,7 @@ final class EmbeddablePart {
 
     private final Part part
     private final RenderContext context
-    private final Closure<Void> onDiagnostics
+    private final Consumer<Collection<Diagnostic>> diagnosticsConsumer
 
     @Nullable
     private final Text text
@@ -21,24 +24,24 @@ final class EmbeddablePart {
     EmbeddablePart(
             Part part,
             RenderContext context,
-            Closure<Void> onDiagnostics,
+            Consumer<Collection<Diagnostic>> diagnosticsConsumer,
             @Nullable Text text
     ) {
         this.part = requireNonNull(part)
         this.context = requireNonNull(context)
-        this.onDiagnostics = requireNonNull(onDiagnostics)
+        this.diagnosticsConsumer = requireNonNull(diagnosticsConsumer)
         this.text = text
     }
 
     String render(Map binding = [:]) {
-        def result = part.type.renderer.render(
+        def result = this.part.type.renderer.render(
                 this.part,
                 binding,
                 this.context,
                 this.text
         )
         if (result.hasDiagnostics()) {
-            this.onDiagnostics.call(result.diagnostics)
+            this.diagnosticsConsumer.accept(result.diagnostics)
             ''
         } else {
             result.get()
diff --git a/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddablePartsMap.groovy b/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddablePartsMap.groovy
index 829199b..bc4878a 100644
--- a/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddablePartsMap.groovy
+++ b/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddablePartsMap.groovy
@@ -2,9 +2,12 @@ package com.jessebrault.ssg.dsl
 
 import com.jessebrault.ssg.render.RenderContext
 import com.jessebrault.ssg.text.Text
+import com.jessebrault.ssg.util.Diagnostic
 import groovy.transform.EqualsAndHashCode
 import org.jetbrains.annotations.Nullable
 
+import java.util.function.Consumer
+
 import static java.util.Objects.requireNonNull
 
 @EqualsAndHashCode(includeFields = true)
@@ -15,13 +18,13 @@ final class EmbeddablePartsMap {
 
     EmbeddablePartsMap(
             RenderContext context,
-            Closure<Void> onDiagnostics,
+            Consumer<Collection<Diagnostic>> diagnosticsConsumer,
             @Nullable Text text = null
     ) {
         requireNonNull(context)
-        requireNonNull(onDiagnostics)
+        requireNonNull(diagnosticsConsumer)
         context.parts.each {
-            this.put(it.path, new EmbeddablePart(it, context, onDiagnostics, text))
+            this[it.path] = new EmbeddablePart(it, context, diagnosticsConsumer, text)
         }
     }
 
diff --git a/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddableText.groovy b/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddableText.groovy
index 53c3818..77f3f6b 100644
--- a/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddableText.groovy
+++ b/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddableText.groovy
@@ -2,24 +2,27 @@ package com.jessebrault.ssg.dsl
 
 import com.jessebrault.ssg.text.FrontMatter
 import com.jessebrault.ssg.text.Text
+import com.jessebrault.ssg.util.Diagnostic
 import groovy.transform.EqualsAndHashCode
 import groovy.transform.Memoized
 import groovy.transform.NullCheck
 import groovy.transform.TupleConstructor
 
+import java.util.function.Consumer
+
 @TupleConstructor(includeFields = true, defaults = false)
 @NullCheck(includeGenerated = true)
 @EqualsAndHashCode(includeFields = true)
 final class EmbeddableText {
 
     private final Text text
-    private final Closure<Void> onDiagnostics
+    private final Consumer<Collection<Diagnostic>> diagnosticsConsumer
 
     @Memoized
     String render() {
         def result = this.text.type.renderer.render(this.text)
         if (result.diagnostics.size() > 0) {
-            this.onDiagnostics.call(result.diagnostics)
+            this.diagnosticsConsumer.accept(result.diagnostics)
             ''
         } else {
             result.get()
@@ -30,7 +33,7 @@ final class EmbeddableText {
     FrontMatter getFrontMatter() {
         def result = this.text.type.frontMatterGetter.get(this.text)
         if (result.hasDiagnostics()) {
-            this.onDiagnostics.call(result.diagnostics)
+            this.diagnosticsConsumer.accept(result.diagnostics)
             new FrontMatter(this.text, [:])
         } else {
             result.get()
@@ -41,7 +44,7 @@ final class EmbeddableText {
     String getExcerpt(int limit) {
         def result = this.text.type.excerptGetter.getExcerpt(this.text, limit)
         if (result.hasDiagnostics()) {
-            this.onDiagnostics.call(result.diagnostics)
+            this.diagnosticsConsumer.accept(result.diagnostics)
             ''
         } else {
             result.get()
diff --git a/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddableTextsCollection.groovy b/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddableTextsCollection.groovy
index 8869af9..7165db2 100644
--- a/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddableTextsCollection.groovy
+++ b/api/src/main/groovy/com/jessebrault/ssg/dsl/EmbeddableTextsCollection.groovy
@@ -1,9 +1,12 @@
 package com.jessebrault.ssg.dsl
 
 import com.jessebrault.ssg.text.Text
+import com.jessebrault.ssg.util.Diagnostic
 import groovy.transform.EqualsAndHashCode
 import groovy.transform.NullCheck
 
+import java.util.function.Consumer
+
 @NullCheck
 @EqualsAndHashCode(includeFields = true)
 final class EmbeddableTextsCollection {
@@ -11,9 +14,9 @@ final class EmbeddableTextsCollection {
     @Delegate
     private final Collection<EmbeddableText> embeddableTexts = []
 
-    EmbeddableTextsCollection(Collection<Text> texts, Closure<Void> onDiagnostics) {
+    EmbeddableTextsCollection(Collection<Text> texts, Consumer<Collection<Diagnostic>> diagnosticsConsumer) {
         texts.each {
-            this << new EmbeddableText(it, onDiagnostics)
+            this << new EmbeddableText(it, diagnosticsConsumer)
         }
     }
 
diff --git a/api/src/main/groovy/com/jessebrault/ssg/dsl/StandardDslMap.groovy b/api/src/main/groovy/com/jessebrault/ssg/dsl/StandardDslMap.groovy
index 5361157..40d986c 100644
--- a/api/src/main/groovy/com/jessebrault/ssg/dsl/StandardDslMap.groovy
+++ b/api/src/main/groovy/com/jessebrault/ssg/dsl/StandardDslMap.groovy
@@ -4,11 +4,12 @@ import com.jessebrault.ssg.dsl.tagbuilder.DynamicTagBuilder
 import com.jessebrault.ssg.dsl.urlbuilder.PathBasedUrlBuilder
 import com.jessebrault.ssg.render.RenderContext
 import com.jessebrault.ssg.text.Text
+import com.jessebrault.ssg.util.Diagnostic
 import groovy.transform.NullCheck
-import groovy.transform.stc.ClosureParams
-import groovy.transform.stc.SimpleType
 import org.slf4j.LoggerFactory
 
+import java.util.function.Consumer
+
 final class StandardDslMap {
 
     @NullCheck(includeGenerated = true)
@@ -16,8 +17,8 @@ final class StandardDslMap {
 
         private final Map<String, Object> custom = [:]
 
+        Consumer<Collection<Diagnostic>> diagnosticsConsumer = { }
         String loggerName = ''
-        Closure<Void> onDiagnostics = { }
         Text text = null
 
         void putCustom(String key, Object value) {
@@ -32,17 +33,10 @@ final class StandardDslMap {
 
     static Map<String, Object> get(
             RenderContext context,
-            @DelegatesTo(value = Builder, strategy = Closure.DELEGATE_FIRST)
-            @ClosureParams(
-                    value = SimpleType,
-                    options = ['com.jessebrault.ssg.dsl.StandardDslMap.Builder']
-            )
-            Closure<Void> builderClosure
+            Consumer<Builder> builderConsumer
     ) {
         def b = new Builder()
-        builderClosure.resolveStrategy = Closure.DELEGATE_FIRST
-        builderClosure.delegate = b
-        builderClosure(b)
+        builderConsumer.accept(b)
 
         [:].tap {
             // standard variables
@@ -51,7 +45,7 @@ final class StandardDslMap {
             it.models = new ModelCollection<Object>(context.models)
             it.parts = new EmbeddablePartsMap(
                     context,
-                    b.onDiagnostics,
+                    b.diagnosticsConsumer,
                     b.text
             )
             it.siteSpec = context.siteSpec
@@ -61,11 +55,11 @@ final class StandardDslMap {
             it.tasks = new TaskCollection(context.tasks)
             it.text = b.text ? new EmbeddableText(
                     b.text,
-                    b.onDiagnostics
+                    b.diagnosticsConsumer
             ) : null
             it.texts = new EmbeddableTextsCollection(
                     context.texts,
-                    b.onDiagnostics
+                    b.diagnosticsConsumer
             )
             it.urlBuilder = new PathBasedUrlBuilder(
                     context.targetPath,
diff --git a/api/src/main/groovy/com/jessebrault/ssg/page/GspPageRenderer.groovy b/api/src/main/groovy/com/jessebrault/ssg/page/GspPageRenderer.groovy
index 8209542..80fb544 100644
--- a/api/src/main/groovy/com/jessebrault/ssg/page/GspPageRenderer.groovy
+++ b/api/src/main/groovy/com/jessebrault/ssg/page/GspPageRenderer.groovy
@@ -21,9 +21,8 @@ final class GspPageRenderer implements PageRenderer {
         def diagnostics = []
         try {
             def result = this.gspRenderer.render(specialPage.text, context) {
+                it.diagnosticsConsumer = diagnostics.&addAll
                 it.loggerName = "GspSpecialPage(${ specialPage.path })"
-                it.onDiagnostics = diagnostics.&addAll
-                return
             }
             Result.of(diagnostics, result.toString())
         } catch (Exception e) {
diff --git a/api/src/main/groovy/com/jessebrault/ssg/part/GspPartRenderer.groovy b/api/src/main/groovy/com/jessebrault/ssg/part/GspPartRenderer.groovy
index efcced0..acddb6a 100644
--- a/api/src/main/groovy/com/jessebrault/ssg/part/GspPartRenderer.groovy
+++ b/api/src/main/groovy/com/jessebrault/ssg/part/GspPartRenderer.groovy
@@ -1,10 +1,10 @@
 package com.jessebrault.ssg.part
 
-import com.jessebrault.ssg.render.StandardGspRenderer
-import com.jessebrault.ssg.util.Diagnostic
 import com.jessebrault.ssg.render.RenderContext
-import com.jessebrault.ssg.util.Result
+import com.jessebrault.ssg.render.StandardGspRenderer
 import com.jessebrault.ssg.text.Text
+import com.jessebrault.ssg.util.Diagnostic
+import com.jessebrault.ssg.util.Result
 import groovy.transform.EqualsAndHashCode
 import org.jetbrains.annotations.Nullable
 
@@ -29,12 +29,11 @@ final class GspPartRenderer implements PartRenderer {
         try {
             def result = this.gspRenderer.render(part.text, context) {
                 it.putCustom('binding', binding)
+                it.diagnosticsConsumer = diagnostics.&addAll
                 it.loggerName = "GspPart(${ part.path })"
-                it.onDiagnostics = diagnostics.&addAll
                 if (text) {
                     it.text = text
                 }
-                return
             }
             Result.of(diagnostics, result.toString())
         } catch (Exception e) {
diff --git a/api/src/main/groovy/com/jessebrault/ssg/render/StandardGspRenderer.groovy b/api/src/main/groovy/com/jessebrault/ssg/render/StandardGspRenderer.groovy
index 4d91a76..ffbd9eb 100644
--- a/api/src/main/groovy/com/jessebrault/ssg/render/StandardGspRenderer.groovy
+++ b/api/src/main/groovy/com/jessebrault/ssg/render/StandardGspRenderer.groovy
@@ -5,6 +5,8 @@ import groovy.text.GStringTemplateEngine
 import groovy.text.TemplateEngine
 import org.codehaus.groovy.control.CompilerConfiguration
 
+import java.util.function.Consumer
+
 final class StandardGspRenderer {
 
     private final TemplateEngine engine
@@ -18,10 +20,9 @@ final class StandardGspRenderer {
     String render(
             String template,
             RenderContext context,
-            @DelegatesTo(value = StandardDslMap.Builder, strategy = Closure.DELEGATE_FIRST)
-            Closure<Void> dslMapBuilderClosure
+            Consumer<StandardDslMap.Builder> dslMapBuilderConsumer
     ) {
-        this.engine.createTemplate(template).make(StandardDslMap.get(context, dslMapBuilderClosure)).toString()
+        this.engine.createTemplate(template).make(StandardDslMap.get(context, dslMapBuilderConsumer)).toString()
     }
 
 }
diff --git a/api/src/main/groovy/com/jessebrault/ssg/template/GspTemplateRenderer.groovy b/api/src/main/groovy/com/jessebrault/ssg/template/GspTemplateRenderer.groovy
index 41eb2ea..02f2ddd 100644
--- a/api/src/main/groovy/com/jessebrault/ssg/template/GspTemplateRenderer.groovy
+++ b/api/src/main/groovy/com/jessebrault/ssg/template/GspTemplateRenderer.groovy
@@ -23,10 +23,9 @@ final class GspTemplateRenderer implements TemplateRenderer {
         def diagnostics = []
         try {
             def result = this.gspRenderer.render(template.text, context) {
+                it.diagnosticsConsumer = diagnostics.&addAll
                 it.loggerName = "GspTemplate(${ template.path })"
-                it.onDiagnostics = diagnostics.&addAll
                 it.text = text
-                return
             }
             Result.of(diagnostics, result)
         } catch (Exception e) {