diff --git a/cube.c b/cube.c
index 082785f..16d7639 100644
--- a/cube.c
+++ b/cube.c
@@ -1,4 +1,5 @@
 #include "globals.h"
+#include <string.h>
 
 static void def_cube();
 static void read_cube();
diff --git a/globals.h b/globals.h
index 433d446..64cd025 100644
--- a/globals.h
+++ b/globals.h
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 #define MAX_MOVES	30
 
diff --git a/setcube.c b/setcube.c
index 9536cbd..53caca0 100644
--- a/setcube.c
+++ b/setcube.c
@@ -1,4 +1,5 @@
 #include "globals.h"
+#include <string.h>
 
 static char corners[8][3][3] = {
     {"ULB", "BUL", "LBU"},
diff --git a/size222.c b/size222.c
index 082bf54..1156f79 100644
--- a/size222.c
+++ b/size222.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 #define NOMAX
 #include "trans/perm7.a"
@@ -8,6 +9,7 @@
 #define MAX_TURNS    (MAX_TWISTS * MAX_CPERMS)
 
 #include "longtype.h"
+#include <string.h>
 
 TYPE turns1[MT];
 TYPE turns2[MT];
diff --git a/size333c.c b/size333c.c
index 9a897b9..ef5ecef 100644
--- a/size333c.c
+++ b/size333c.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 #define EQUIV
 #define NOMAX
@@ -29,6 +30,7 @@
 #endif /* CCPERM */
 
 #include "longtype.h"
+#include <string.h>
 
 TYPE turns1[MT];
 TYPE turns2[MT];
diff --git a/sizedom.c b/sizedom.c
index 534c98b..fe724f9 100644
--- a/sizedom.c
+++ b/sizedom.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 #define SUBGROUP
 #define EQUIV
@@ -30,6 +31,7 @@
 #endif /* CEPERM */
 
 #include "longtype.h"
+#include <string.h>
 
 TYPE turns1[MT];
 TYPE turns2[MT];
diff --git a/sizekoc1.c b/sizekoc1.c
index 4e8f97a..39c6ab7 100644
--- a/sizekoc1.c
+++ b/sizekoc1.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 #define EQUIV
 #define NOMAX
@@ -19,6 +20,7 @@
 #define MAX_TURNS    (TWIST_MAGIC * MAX_FLIPS * MAX_CHOICES)
 
 #include "longtype.h"
+#include <string.h>
 
 TYPE turns1[MT];
 TYPE turns2[MT];
diff --git a/sizekoc2.c b/sizekoc2.c
index 90c4b46..2062f8d 100644
--- a/sizekoc2.c
+++ b/sizekoc2.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 #define EQUIV
 #define NOMAX
@@ -19,6 +20,7 @@
 #define MAX_TURNS    (CPERM_MAGIC * MAX_EPERMS * MAX_SPERMS)
 
 #include "longtype.h"
+#include <string.h>
 
 TYPE turns1[MT];
 TYPE turns2[MT];
diff --git a/sizesquare.c b/sizesquare.c
index 89503ef..521ede4 100644
--- a/sizesquare.c
+++ b/sizesquare.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 #define NOMAX
 #include "trans/perm4.a"
@@ -8,6 +9,7 @@
 #define MAX_TURNS    (MAX_EPERMS2 * MAX_CPERMS2)
 
 #include "longtype.h"
+#include <string.h>
 
 TYPE turns1[MT];
 TYPE turns2[MT];