diff --git a/legacy/embryo/configure.in b/legacy/embryo/configure.in
index e015b69fb8..dfc27291f5 100644
--- a/legacy/embryo/configure.in
+++ b/legacy/embryo/configure.in
@@ -18,6 +18,7 @@ AC_HEADER_STDC
 AC_C_CONST
 AM_ENABLE_SHARED
 AM_PROG_LIBTOOL
+AC_FUNC_ALLOCA
 
 if test "x${exec_prefix}" = "xNONE"; then
   if test "x${prefix}" = "xNONE"; then
diff --git a/legacy/embryo/src/lib/embryo_private.h b/legacy/embryo/src/lib/embryo_private.h
index 32ef429c58..f630df5b39 100644
--- a/legacy/embryo/src/lib/embryo_private.h
+++ b/legacy/embryo/src/lib/embryo_private.h
@@ -11,7 +11,10 @@
 #include <limits.h>
 #include <stdarg.h>
 #include <string.h>
+
+#if HAVE_ALLOCA_H
 #include <alloca.h>
+#endif
 
 typedef enum _Embryo_Opcode Embryo_Opcode;