diff --git a/doc/manuals/Makefile b/doc/manuals/Makefile
index 2f87b57..63bd422 100644
--- a/doc/manuals/Makefile
+++ b/doc/manuals/Makefile
@@ -4,6 +4,6 @@
 
 ASCIIDOC = icE1usb-usermanual.adoc
 include $(OSMO_GSM_MANUALS_DIR)/build/Makefile.asciidoc.inc
-icE1usb-usermanual.pdf: chapters/*.adoc
+icE1usb-usermanual.pdf: chapters/icE1usb/*.adoc
 
 include $(OSMO_GSM_MANUALS_DIR)/build/Makefile.common.inc