diff --git a/have.h b/have.h
index db92058d..cd7ad06c 100644
--- a/have.h
+++ b/have.h
@@ -43,6 +43,10 @@
 #include <inttypes.h>
 #endif
 
+#ifdef HAVE_ALLOCA_H
+#include <alloca.h>
+#endif
+
 /* Include system specific headers */
 
 #ifdef HAVE_SYSLOG_H