diff --git a/libguile/gsubr.c b/libguile/gsubr.c
index 2b9a29dd1..5e5b4c10e 100644
--- a/libguile/gsubr.c
+++ b/libguile/gsubr.c
@@ -20,6 +20,8 @@
 # include <config.h>
 #endif
 
+#include <alloca.h>
+
 #include <stdio.h>
 #include <stdarg.h>