diff --git a/datasette/publish/heroku.py b/datasette/publish/heroku.py
index 368f37bc..5705500f 100644
--- a/datasette/publish/heroku.py
+++ b/datasette/publish/heroku.py
@@ -183,7 +183,9 @@ def temporary_heroku_directory(
             )
             extras.extend(["--static", "{}:{}".format(mount_point, mount_point)])
 
-        quoted_files = " ".join(map(shlex.quote, file_names))
+        quoted_files = " ".join(
+            ["-i {}".format(shlex.quote(file_name)) for file_name in file_names]
+        )
         procfile_cmd = "web: datasette serve --host 0.0.0.0 {quoted_files} --cors --port $PORT --inspect-file inspect-data.json {extras}".format(
             quoted_files=quoted_files, extras=" ".join(extras)
         )
diff --git a/datasette/utils.py b/datasette/utils.py
index b4e0d726..2031126b 100644
--- a/datasette/utils.py
+++ b/datasette/utils.py
@@ -295,7 +295,8 @@ def make_dockerfile(
     version_note,
 ):
     cmd = ["datasette", "serve", "--host", "0.0.0.0"]
-    cmd.append('", "'.join(files))
+    for filename in files:
+        cmd.extend(["-i", filename])
     cmd.extend(["--cors", "--inspect-file", "inspect-data.json"])
     if metadata_file:
         cmd.extend(["--metadata", "{}".format(metadata_file)])