diff --git a/lang/m2/comp/chk_expr.c b/lang/m2/comp/chk_expr.c
index 25f0f2d5c..d9a39c3a2 100644
--- a/lang/m2/comp/chk_expr.c
+++ b/lang/m2/comp/chk_expr.c
@@ -12,6 +12,8 @@
 /*	Check expressions, and try to evaluate them as far as possible.
 */
 
+#include   <stdlib.h>
+#include   <string.h>
 #include	"debug.h"
 
 #include	<em_arith.h>
diff --git a/lang/m2/comp/def.c b/lang/m2/comp/def.c
index 32074ea43..711f2d7e4 100644
--- a/lang/m2/comp/def.c
+++ b/lang/m2/comp/def.c
@@ -9,6 +9,8 @@
 
 /* $Id$ */
 
+#include   <stdlib.h>
+#include   <string.h>
 #include	"debug.h"
 
 #include	<alloc.h>
diff --git a/lang/m2/comp/input.c b/lang/m2/comp/input.c
index 05ce5824e..4c516a44e 100644
--- a/lang/m2/comp/input.c
+++ b/lang/m2/comp/input.c
@@ -9,6 +9,9 @@
 
 /* $Id$ */
 
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
 #include	"f_info.h"
 struct f_info	file_info;
 #include	"input.h"
diff --git a/lang/m2/comp/program.g b/lang/m2/comp/program.g
index a83b8a148..abc75bd35 100644
--- a/lang/m2/comp/program.g
+++ b/lang/m2/comp/program.g
@@ -10,6 +10,8 @@
 /* $Id$ */
 
 {
+#include    <stdlib.h>
+#include    <string.h>
 #include	"debug.h"
 
 #include	<alloc.h>
diff --git a/lang/m2/comp/walk.c b/lang/m2/comp/walk.c
index 05110be39..c79daed19 100644
--- a/lang/m2/comp/walk.c
+++ b/lang/m2/comp/walk.c
@@ -13,6 +13,8 @@
 	code for these parts.
 */
 
+#include   <stdlib.h>
+#include   <string.h>
 #include	"debug.h"
 
 #include	<em_arith.h>