diff --git a/setup/build.py b/setup/build.py
index b6c7e8909a..edfff97b83 100644
--- a/setup/build.py
+++ b/setup/build.py
@@ -106,7 +106,7 @@ def parse_extension(ext):
         cflags = kw['cflags']
         prefix = '/D' if iswindows else '-D'
         cflags.extend(prefix + x for x in defines.split())
-    for k in 'inc_dirs sources headers sip_files'.split():
+    for k in 'inc_dirs lib_dirs sources headers sip_files'.split():
         v = get(k)
         if v:
             kw[k] = expand_file_list(v.split())
diff --git a/setup/extensions.json b/setup/extensions.json
index f745d8fc15..6f3e7d9c0e 100644
--- a/setup/extensions.json
+++ b/setup/extensions.json
@@ -66,7 +66,8 @@
     },
     {
         "name": "sqlite_custom",
-        "sources": "calibre/library/sqlite_custom.c"
+        "sources": "calibre/library/sqlite_custom.c",
+        "inc_dirs": "!sqlite_inc_dirs"
     },
     {
         "name": "chmlib",