diff --git a/cli/src/main/groovy/com/jessebrault/ssg/AbstractBuildCommand.groovy b/cli/src/main/groovy/com/jessebrault/ssg/AbstractBuildCommand.groovy
index 80b8cd0..dba4ed5 100644
--- a/cli/src/main/groovy/com/jessebrault/ssg/AbstractBuildCommand.groovy
+++ b/cli/src/main/groovy/com/jessebrault/ssg/AbstractBuildCommand.groovy
@@ -1,6 +1,7 @@
 package com.jessebrault.ssg
 
 import com.jessebrault.ssg.buildscript.GroovyBuildScriptRunner
+import com.jessebrault.ssg.output.OutputPage
 import com.jessebrault.ssg.part.GspPartRenderer
 import com.jessebrault.ssg.part.PartFilePartsProvider
 import com.jessebrault.ssg.part.PartType
@@ -75,10 +76,10 @@ abstract class AbstractBuildCommand extends AbstractSubCommand {
                     logger.error(it.message)
                 }
             } else {
-                result.v2.each { GeneratedPage generatedPage ->
-                    def target = new File(it.outDir, generatedPage.path + '.html')
+                result.v2.each { OutputPage outputPage ->
+                    def target = new File(it.outDir, outputPage.path)
                     target.createParentDirectories()
-                    target.write(generatedPage.html)
+                    target.write(outputPage.content)
                 }
             }
         }
diff --git a/lib/src/main/groovy/com/jessebrault/ssg/GeneratedPage.groovy b/lib/src/main/groovy/com/jessebrault/ssg/GeneratedPage.groovy
deleted file mode 100644
index 6b92787..0000000
--- a/lib/src/main/groovy/com/jessebrault/ssg/GeneratedPage.groovy
+++ /dev/null
@@ -1,20 +0,0 @@
-package com.jessebrault.ssg
-
-import groovy.transform.EqualsAndHashCode
-import groovy.transform.NullCheck
-import groovy.transform.TupleConstructor
-
-@TupleConstructor(includeFields = true, defaults = false)
-@NullCheck
-@EqualsAndHashCode
-class GeneratedPage {
-
-    String path
-    String html
-
-    @Override
-    String toString() {
-        "GeneratedPage(path: ${ this.path })"
-    }
-
-}
diff --git a/lib/src/main/groovy/com/jessebrault/ssg/SimpleStaticSiteGenerator.groovy b/lib/src/main/groovy/com/jessebrault/ssg/SimpleStaticSiteGenerator.groovy
index 04504ed..53d2a43 100644
--- a/lib/src/main/groovy/com/jessebrault/ssg/SimpleStaticSiteGenerator.groovy
+++ b/lib/src/main/groovy/com/jessebrault/ssg/SimpleStaticSiteGenerator.groovy
@@ -1,5 +1,6 @@
 package com.jessebrault.ssg
 
+import com.jessebrault.ssg.output.OutputPage
 import com.jessebrault.ssg.text.FrontMatter
 import groovy.transform.EqualsAndHashCode
 import groovy.transform.NullCheck
@@ -19,7 +20,7 @@ class SimpleStaticSiteGenerator implements StaticSiteGenerator {
     private static final Marker exit = MarkerFactory.getMarker('EXIT')
 
     @Override
-    Tuple2<Collection<Diagnostic>, Collection<GeneratedPage>> generate(Build build) {
+    Tuple2<Collection<Diagnostic>, Collection<OutputPage>> generate(Build build) {
         logger.trace(enter, 'build: {}', build)
         logger.info('processing build with name: {}', build.name)
 
@@ -35,7 +36,7 @@ class SimpleStaticSiteGenerator implements StaticSiteGenerator {
 
         def globals = build.globals
         Collection<Diagnostic> diagnostics = []
-        Collection<GeneratedPage> generatedPages = []
+        Collection<OutputPage> generatedPages = []
 
         // Generate pages from each text, but only those that have a 'template' frontMatter field with a valid value
         texts.each {
@@ -87,7 +88,7 @@ class SimpleStaticSiteGenerator implements StaticSiteGenerator {
             }
 
             // Create a GeneratedPage
-            generatedPages << new GeneratedPage(it.path, renderedTemplate)
+            generatedPages << OutputPage.of(it, '.html', renderedTemplate)
         }
 
         // Generate special pages
@@ -105,7 +106,7 @@ class SimpleStaticSiteGenerator implements StaticSiteGenerator {
             }
 
             // Create a GeneratedPage
-            generatedPages << new GeneratedPage(it.path, renderedSpecialPage)
+            generatedPages << OutputPage.of(it, '.html', renderedSpecialPage)
         }
 
         logger.trace(exit, '\n\tdiagnostics: {}\n\tgeneratedPages: {}', diagnostics, generatedPages)
diff --git a/lib/src/main/groovy/com/jessebrault/ssg/StaticSiteGenerator.groovy b/lib/src/main/groovy/com/jessebrault/ssg/StaticSiteGenerator.groovy
index 8553be4..37573c9 100644
--- a/lib/src/main/groovy/com/jessebrault/ssg/StaticSiteGenerator.groovy
+++ b/lib/src/main/groovy/com/jessebrault/ssg/StaticSiteGenerator.groovy
@@ -1,5 +1,7 @@
 package com.jessebrault.ssg
 
+import com.jessebrault.ssg.output.OutputPage
+
 interface StaticSiteGenerator {
-    Tuple2<Collection<Diagnostic>, Collection<GeneratedPage>> generate(Build build)
+    Tuple2<Collection<Diagnostic>, Collection<OutputPage>> generate(Build build)
 }
diff --git a/lib/src/main/groovy/com/jessebrault/ssg/input/InputPage.groovy b/lib/src/main/groovy/com/jessebrault/ssg/input/InputPage.groovy
new file mode 100644
index 0000000..1e37f22
--- /dev/null
+++ b/lib/src/main/groovy/com/jessebrault/ssg/input/InputPage.groovy
@@ -0,0 +1,5 @@
+package com.jessebrault.ssg.input
+
+interface InputPage {
+    String getPath()
+}
\ No newline at end of file
diff --git a/lib/src/main/groovy/com/jessebrault/ssg/output/OutputPage.groovy b/lib/src/main/groovy/com/jessebrault/ssg/output/OutputPage.groovy
new file mode 100644
index 0000000..c4a17b1
--- /dev/null
+++ b/lib/src/main/groovy/com/jessebrault/ssg/output/OutputPage.groovy
@@ -0,0 +1,30 @@
+package com.jessebrault.ssg.output
+
+import com.jessebrault.ssg.input.InputPage
+import groovy.transform.EqualsAndHashCode
+import groovy.transform.NullCheck
+
+import static com.jessebrault.ssg.util.ExtensionsUtil.stripExtension
+
+@NullCheck
+@EqualsAndHashCode
+final class OutputPage {
+
+    static OutputPage of(InputPage inputFile, String extension, String content) {
+        new OutputPage(stripExtension(inputFile.path) + extension, content)
+    }
+
+    final String path
+    final String content
+
+    private OutputPage(String path, String content) {
+        this.path = path
+        this.content = content
+    }
+
+    @Override
+    String toString() {
+        "GeneratedPage(path: ${ this.path })"
+    }
+
+}
diff --git a/lib/src/main/groovy/com/jessebrault/ssg/specialpage/GspSpecialPageRenderer.groovy b/lib/src/main/groovy/com/jessebrault/ssg/specialpage/GspSpecialPageRenderer.groovy
index df607f1..d084d16 100644
--- a/lib/src/main/groovy/com/jessebrault/ssg/specialpage/GspSpecialPageRenderer.groovy
+++ b/lib/src/main/groovy/com/jessebrault/ssg/specialpage/GspSpecialPageRenderer.groovy
@@ -32,9 +32,7 @@ class GspSpecialPageRenderer implements SpecialPageRenderer {
                     parts: new EmbeddablePartsMap(parts, globals, diagnostics.&addAll, specialPage.path),
                     path: specialPage.path,
                     tagBuilder: new DynamicTagBuilder(),
-                    texts: new EmbeddableTextsCollection(texts, globals, { Collection<Diagnostic> textDiagnostics ->
-                        diagnostics.addAll(textDiagnostics)
-                    }),
+                    texts: new EmbeddableTextsCollection(texts, globals, diagnostics.&addAll),
                     urlBuilder: new PathBasedUrlBuilder(specialPage.path)
             ])
             new Tuple2<>(diagnostics, result.toString())
diff --git a/lib/src/main/groovy/com/jessebrault/ssg/specialpage/SpecialPage.groovy b/lib/src/main/groovy/com/jessebrault/ssg/specialpage/SpecialPage.groovy
index 869a412..c3df5fa 100644
--- a/lib/src/main/groovy/com/jessebrault/ssg/specialpage/SpecialPage.groovy
+++ b/lib/src/main/groovy/com/jessebrault/ssg/specialpage/SpecialPage.groovy
@@ -1,5 +1,6 @@
 package com.jessebrault.ssg.specialpage
 
+import com.jessebrault.ssg.input.InputPage
 import groovy.transform.EqualsAndHashCode
 import groovy.transform.NullCheck
 import groovy.transform.TupleConstructor
@@ -7,7 +8,7 @@ import groovy.transform.TupleConstructor
 @TupleConstructor(defaults = false)
 @NullCheck
 @EqualsAndHashCode
-class SpecialPage {
+class SpecialPage implements InputPage {
 
     String text
     String path
diff --git a/lib/src/main/groovy/com/jessebrault/ssg/text/Text.groovy b/lib/src/main/groovy/com/jessebrault/ssg/text/Text.groovy
index ad6fccc..a81275d 100644
--- a/lib/src/main/groovy/com/jessebrault/ssg/text/Text.groovy
+++ b/lib/src/main/groovy/com/jessebrault/ssg/text/Text.groovy
@@ -1,5 +1,6 @@
 package com.jessebrault.ssg.text
 
+import com.jessebrault.ssg.input.InputPage
 import groovy.transform.EqualsAndHashCode
 import groovy.transform.NullCheck
 import groovy.transform.TupleConstructor
@@ -7,7 +8,7 @@ import groovy.transform.TupleConstructor
 @TupleConstructor(defaults = false)
 @NullCheck
 @EqualsAndHashCode
-class Text {
+class Text implements InputPage {
 
     String text
     String path
diff --git a/lib/src/test/groovy/com/jessebrault/ssg/SimpleStaticSiteGeneratorIntegrationTests.groovy b/lib/src/test/groovy/com/jessebrault/ssg/SimpleStaticSiteGeneratorIntegrationTests.groovy
index 614df3d..2a009b1 100644
--- a/lib/src/test/groovy/com/jessebrault/ssg/SimpleStaticSiteGeneratorIntegrationTests.groovy
+++ b/lib/src/test/groovy/com/jessebrault/ssg/SimpleStaticSiteGeneratorIntegrationTests.groovy
@@ -17,6 +17,7 @@ import com.jessebrault.ssg.text.TextType
 import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Test
 
+import static com.jessebrault.ssg.testutil.DiagnosticsUtil.assertEmptyDiagnostics
 import static org.junit.jupiter.api.Assertions.*
 
 class SimpleStaticSiteGeneratorIntegrationTests {
@@ -65,12 +66,12 @@ class SimpleStaticSiteGeneratorIntegrationTests {
 
         def result = this.ssg.generate(this.build)
 
-        assertTrue(result.v1.size() == 0)
+        assertEmptyDiagnostics(result)
         assertTrue(result.v2.size() == 1)
 
         def p0 = result.v2[0]
-        assertEquals('test', p0.path)
-        assertEquals('<p><strong>Hello, World!</strong></p>\n', p0.html)
+        assertEquals('test.html', p0.path)
+        assertEquals('<p><strong>Hello, World!</strong></p>\n', p0.content)
     }
 
     @Test
@@ -85,39 +86,40 @@ class SimpleStaticSiteGeneratorIntegrationTests {
 
         def result = this.ssg.generate(this.build)
 
-        assertTrue(result.v1.size() == 0)
+        assertEmptyDiagnostics(result)
         assertTrue(result.v2.size() == 1)
 
         def p0 = result.v2[0]
-        assertEquals('nested/nested', p0.path)
-        assertEquals('<p><strong>Hello, World!</strong></p>\n', p0.html)
+        assertEquals('nested/nested.html', p0.path)
+        assertEquals('<p><strong>Hello, World!</strong></p>\n', p0.content)
     }
 
     @Test
     void outputsSpecialPage() {
-        new FileTreeBuilder(this.specialPagesDir).file('special.gsp', $/<%= texts.find { it.path == 'test' }.render() %>/$)
+        new FileTreeBuilder(this.specialPagesDir)
+                .file('special.gsp', $/<%= texts.find { it.path == 'test.md' }.render() %>/$)
         new FileTreeBuilder(this.templatesDir).file('template.gsp', '<%= 1 + 1 %>')
         new FileTreeBuilder(this.textsDir).file('test.md', '---\ntemplate: template.gsp\n---\nHello, World!')
 
         def result = this.ssg.generate(this.build)
 
-        assertEquals(0, result.v1.size())
+        assertEmptyDiagnostics(result)
         assertEquals(2, result.v2.size())
 
-        def testPage = result.v2.find { it.path == 'test' }
+        def testPage = result.v2.find { it.path == 'test.html' }
         assertNotNull(testPage)
-        assertEquals('2', testPage.html)
+        assertEquals('2', testPage.content)
 
-        def specialPage = result.v2.find { it.path == 'special' }
+        def specialPage = result.v2.find { it.path == 'special.html' }
         assertNotNull(specialPage)
-        assertEquals('<p>Hello, World!</p>\n', specialPage.html)
+        assertEquals('<p>Hello, World!</p>\n', specialPage.content)
     }
 
     @Test
     void doesNotGenerateIfNoTemplateInFrontMatter() {
         new File(this.textsDir, 'test.md').write('Hello, World!')
         def result = this.ssg.generate(this.build)
-        assertEquals(0, result.v1.size())
+        assertEmptyDiagnostics(result)
         assertEquals(0, result.v2.size())
     }