diff --git a/src/main/java/org/apache/maven/plugins/javadoc/AbstractJavadocMojo.java b/src/main/java/org/apache/maven/plugins/javadoc/AbstractJavadocMojo.java
index 5610ef061..025b8d2a7 100644
--- a/src/main/java/org/apache/maven/plugins/javadoc/AbstractJavadocMojo.java
+++ b/src/main/java/org/apache/maven/plugins/javadoc/AbstractJavadocMojo.java
@@ -1936,12 +1936,6 @@ protected void executeReport(Locale unusedLocale) throws MavenReportException {
         }
         javadocOutputDirectory.mkdirs();
 
-        // ----------------------------------------------------------------------
-        // Copy all resources
-        // ----------------------------------------------------------------------
-
-        copyAllResources(javadocOutputDirectory);
-
         // ----------------------------------------------------------------------
         // Create command line for Javadoc
         // ----------------------------------------------------------------------
@@ -4971,12 +4965,17 @@ private void addTagletsFromTagletArtifacts(List<String> arguments) throws MavenR
      * @throws MavenReportException if any errors occur
      */
     private void executeJavadocCommandLine(Commandline cmd, File javadocOutputDirectory) throws MavenReportException {
+        // Resources must be copied only when Javadoc is actually (re)generated. copyAllResources removes
+        // excluded doc-file subdirectories from the output directory; if it ran while generation was skipped
+        // as up to date, those files would be deleted without being regenerated, leaving the output incomplete.
         if (staleDataPath != null) {
             if (!isUpToDate(cmd)) {
+                copyAllResources(javadocOutputDirectory);
                 doExecuteJavadocCommandLine(cmd, javadocOutputDirectory);
                 StaleHelper.writeStaleData(cmd, staleDataPath.toPath());
             }
         } else {
+            copyAllResources(javadocOutputDirectory);
             doExecuteJavadocCommandLine(cmd, javadocOutputDirectory);
         }
     }