diff --git a/guile-readline/Makefile.am b/guile-readline/Makefile.am
index 2726896a3..50a179e73 100644
--- a/guile-readline/Makefile.am
+++ b/guile-readline/Makefile.am
@@ -24,7 +24,7 @@ AUTOMAKE_OPTIONS = foreign
 ## Check for headers in $(srcdir)/.., so that #include
 ## <libguile/MUMBLE.h> will find MUMBLE.h in this dir when we're
 ## building.
-INCLUDES = -I.. -I$(srcdir)/.. ${THREAD_CPPFLAGS}
+INCLUDES = -I.. -I$(srcdir)/.. -I$(srcdir)/../libguile ${THREAD_CPPFLAGS}
 
 GUILE_SNARF = ../libguile/guile-snarf