diff --git a/guile-readline/readline.c b/guile-readline/readline.c
index 9ee640363..b6e290b50 100644
--- a/guile-readline/readline.c
+++ b/guile-readline/readline.c
@@ -27,6 +27,7 @@
 
 #ifdef HAVE_RL_GETC_FUNCTION
 #include <stdio.h>
+#include <string.h>
 #include <unistd.h>
 #include <sys/time.h>
 #include <sys/select.h>