diff --git a/libguile/coop-threads.c b/libguile/coop-threads.c
index cf28fc4dd..81f227ad5 100644
--- a/libguile/coop-threads.c
+++ b/libguile/coop-threads.c
@@ -46,6 +46,8 @@
 
 #include "validate.h"
 #include "coop-threads.h"
+#include "root.h"
+#include "strings.h"
 
 /* A counter of the current number of threads */
 size_t scm_thread_count = 0;