diff --git a/doc/sphinx/kerneldoc.py b/doc/sphinx/kerneldoc.py
index 8189c33..01a5542 100644
--- a/doc/sphinx/kerneldoc.py
+++ b/doc/sphinx/kerneldoc.py
@@ -138,7 +138,7 @@
                     lineoffset = int(match.group(1)) - 1
                     # we must eat our comments since the upset the markup
                 else:
-                    doc = env.srcdir + "/" + env.docname + ":" + str(self.lineno)
+                    doc = str(env.srcdir) + "/" + env.docname + ":" + str(self.lineno)
                     result.append(line, doc + ": " + filename, lineoffset)
                     lineoffset += 1
 
diff --git a/doc/sphinx/kfigure.py b/doc/sphinx/kfigure.py
index 7887048..dea7f91 100644
--- a/doc/sphinx/kfigure.py
+++ b/doc/sphinx/kfigure.py
@@ -266,7 +266,7 @@
     if dst_fname:
         # the builder needs not to copy one more time, so pop it if exists.
         translator.builder.images.pop(img_node['uri'], None)
-        _name = dst_fname[len(translator.builder.outdir) + 1:]
+        _name = dst_fname[len(str(translator.builder.outdir)) + 1:]
 
         if isNewer(dst_fname, src_fname):
             kernellog.verbose(app,