diff --git a/x11vnc/Makefile.am b/x11vnc/Makefile.am
index cef82f3..12ca9f1 100644
--- a/x11vnc/Makefile.am
+++ b/x11vnc/Makefile.am
@@ -36,7 +36,7 @@ x11vnc_SOURCES = 8to24.c appshare.c avahi.c cleanup.c connections.c cursor.c gui
 if HAVE_SYSTEM_LIBVNCSERVER
 INCLUDES_LIBVNCSERVER = @SYSTEM_LIBVNCSERVER_CFLAGS@
 else
-INCLUDES_LIBVNCSERVER =
+INCLUDES_LIBVNCSERVER = -I${top_srcdir}
 endif
 INCLUDES = $(INCLUDES_LIBVNCSERVER) @X_CFLAGS@ @AVAHI_CFLAGS@