diff --git a/java/hiddenapi_monolithic.go b/java/hiddenapi_monolithic.go
index 52f0770..9d963d2 100644
--- a/java/hiddenapi_monolithic.go
+++ b/java/hiddenapi_monolithic.go
@@ -58,30 +58,20 @@
 	// Merge all the information from the classpathElements. The fragments form a DAG so it is possible that
 	// this will introduce duplicates so they will be resolved after processing all the classpathElements.
 	for _, element := range classpathElements {
-		var classesJars android.Paths
 		switch e := element.(type) {
 		case *ClasspathLibraryElement:
-			classesJars = retrieveClassesJarsFromModule(e.Module())
+			classesJars := retrieveClassesJarsFromModule(e.Module())
+			monolithicInfo.ClassesJars = append(monolithicInfo.ClassesJars, classesJars...)
 
 		case *ClasspathFragmentElement:
 			fragment := e.Module()
 			if ctx.OtherModuleHasProvider(fragment, HiddenAPIInfoProvider) {
 				info := ctx.OtherModuleProvider(fragment, HiddenAPIInfoProvider).(HiddenAPIInfo)
 				monolithicInfo.append(&info)
-
-				// If the bootclasspath fragment actually perform hidden API processing itself then use the
-				// CSV files it provides and do not bother processing the classesJars files. This ensures
-				// consistent behavior between source and prebuilt as prebuilt modules do not provide
-				// classesJars.
-				if info.AllFlagsPath != nil {
-					continue
-				}
+			} else {
+				ctx.ModuleErrorf("%s does not provide hidden API information", fragment)
 			}
-
-			classesJars = extractClassesJarsFromModules(e.Contents)
 		}
-
-		monolithicInfo.ClassesJars = append(monolithicInfo.ClassesJars, classesJars...)
 	}
 
 	// Dedup paths.