diff -r f798a913d729 -r b7929e1dc4fb src/Pure/Admin/check_sources.scala
--- a/src/Pure/Admin/check_sources.scala	Sun Feb 09 11:14:59 2025 +0100
+++ b/src/Pure/Admin/check_sources.scala	Sun Feb 09 12:14:09 2025 +0100
@@ -50,7 +50,7 @@
     val hg = Mercurial.repository(root)
     for {
       file <- hg.known_files()
-      if File.is_thy(file) || File.is_ML(file) || file.endsWith("/ROOT")
+      if File.is_scala(file) || File.is_thy(file) || File.is_ML(file) || file.endsWith("/ROOT")
     } check_file(root + Path.explode(file))
   }
 
@@ -64,7 +64,7 @@
         val getopts = Getopts("""
 Usage: isabelle check_sources [ROOT_DIRS...]
 
-  Check .thy, .ML, ROOT against known files of Mercurial ROOT_DIRS.
+  Check .scala, .thy, .ML, ROOT against known files of Mercurial ROOT_DIRS.
 """)
 
         val specs = getopts(args)