diff --git a/buildSrc/src/main/java/org/springframework/boot/build/antora/GenerateAntoraPlaybook.java b/buildSrc/src/main/java/org/springframework/boot/build/antora/GenerateAntoraPlaybook.java
index 6b6a408ee9..adbf9e55a2 100644
--- a/buildSrc/src/main/java/org/springframework/boot/build/antora/GenerateAntoraPlaybook.java
+++ b/buildSrc/src/main/java/org/springframework/boot/build/antora/GenerateAntoraPlaybook.java
@@ -93,7 +93,8 @@ public abstract class GenerateAntoraPlaybook extends DefaultTask {
 		}
 	}
 
-	private Map<String, Object> getData() throws IOException {
+	@Input
+	final Map<String, Object> getData() throws IOException {
 		Map<String, Object> data = loadPlaybookTemplate();
 		addExtensions(data);
 		addSources(data);