diff --git a/epan/CMakeLists.txt b/epan/CMakeLists.txt
index ff0a6072c9..1a8a103f23 100644
--- a/epan/CMakeLists.txt
+++ b/epan/CMakeLists.txt
@@ -429,20 +429,11 @@ set_target_properties(wscbor_test PROPERTIES
     EXCLUDE_FROM_DEFAULT_BUILD True
 )
 
-set(ENUM_FILES
-	epan/address.h
-	epan/ipproto.h
-	epan/proto.h
-	epan/ftypes/ftypes.h
-)
-
 # This tries to parse C headers using Python to extract enums for
 # introspection. It is slow and has some particular dependencies.
 # It's also not foolproof. It should not be part of the ALL target.
 add_custom_target(gen-enums
 	COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_SOURCE_DIR}/tools/make-enums.py
-		--outfile ${CMAKE_CURRENT_SOURCE_DIR}/introspection-enums.c
-		${ENUM_FILES}
 	WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
 )
 
diff --git a/tools/make-enums.py b/tools/make-enums.py
index 459fd4a5d8..703fabcffa 100755
--- a/tools/make-enums.py
+++ b/tools/make-enums.py
@@ -20,12 +20,34 @@ import sys
 import argparse
 from pyclibrary import CParser
 
+default_infiles = [
+    "epan/address.h",
+    "epan/ipproto.h",
+    "epan/proto.h",
+    "epan/ftypes/ftypes.h",
+]
+
+default_outfile = "epan/introspection-enums.c"
+
 argp = argparse.ArgumentParser()
 argp.add_argument("-o", "--outfile")
 argp.add_argument("infiles", nargs="*")
 args = argp.parse_args()
 
-parser = CParser(args.infiles)
+if args.infiles:
+    infiles = args.infiles
+else:
+    infiles = default_infiles
+
+if args.outfile:
+    outfile = args.outfile
+else:
+    outfile = default_outfile
+
+print("input: {}".format(infiles))
+print("output: {}".format(outfile))
+
+parser = CParser(infiles)
 
 source = """\
 /*
@@ -46,7 +68,7 @@ source = """\
  */
 """ % (os.path.basename(sys.argv[0]))
 
-for f in args.infiles:
+for f in infiles:
     source += '#include <{}>\n'.format(f)
 
 source += """
@@ -69,12 +91,9 @@ source += """\
 """
 
 try:
-    if args.outfile:
-        fh = open(args.outfile, 'w')
-    else:
-        fh = sys.stdout
+    fh = open(outfile, 'w')
 except OSError:
-    sys.exit('Unable to write ' + args.outfile + '.\n')
+    sys.exit('Unable to write ' + outfile + '.\n')
 
 fh.write(source)
 fh.close()