diff --git a/FAQ.md b/FAQ.md
index 0c8408e..9cc300d 100644
--- a/FAQ.md
+++ b/FAQ.md
@@ -210,6 +210,14 @@ One approach ccls explored before was to compile its import file `a.c`, but it
 caused severe performance issues for some projects.  For smaller files this
 does not matter and checking for a header guard may help the situation.
 
+If missing declarations are known to be provided by `base.h`, you can specify `--include`,
+e.g.
+
+```
+%compile_commands.json
+%h %hpp --include=base.h
+```
+
 ## Multi-version headers
 
 A header can be included in different translation units with different