diff --git a/gtk/aliasfilescheck.sh b/gtk/aliasfilescheck.sh
index 31b49d451..59faa2326 100755
--- a/gtk/aliasfilescheck.sh
+++ b/gtk/aliasfilescheck.sh
@@ -5,7 +5,14 @@ if test "x$gtk_all_c_sources" = x; then
 	exit 1
 fi
 
-grep 'IN_FILE' ${srcdir-.}/gtk.symbols | sed 's/.*(//;s/).*//' | grep __ | sort -u > expected-files
-{ cd ${srcdir-.}; grep '^ *# *define __' $gtk_all_c_sources; } | sed 's/.*define //;s/ *$//' | sort > actual-files
+srcdir=${srcdir-.}
+
+grep 'IN_FILE' "$srcdir/gtk.symbols" | sed 's/^[^(]*(//;s/).*//;s/__GTK_MARSHAL_MARSHAL_C__/__gtk_marshal_MARSHAL_C__/' | grep __ | sort -u > expected-files
+{
+	for file in $gtk_all_c_sources; do
+		test -f "$file" || file="$srcdir/$file"
+		grep '^ *# *define __' "$file"
+	done
+} | sed 's/.*define //;s/ *$//;s/__GTK_MARSHAL_MARSHAL_C__/__gtk_marshal_MARSHAL_C__/' | sort > actual-files
 
 diff expected-files actual-files && rm -f expected-files actual-files