diff --git a/c/scheme48vm-prelude.h b/c/scheme48vm-prelude.h
index ee622b1..6e59a1a 100644
--- a/c/scheme48vm-prelude.h
+++ b/c/scheme48vm-prelude.h
@@ -1,5 +1,6 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h> /* memcpy, strlen */
 
 #include "c-mods.h"
 #include "write-barrier.h"
diff --git a/ps-compiler/compile-gc.scm b/ps-compiler/compile-gc.scm
index 1a57497..eed43f6 100644
--- a/ps-compiler/compile-gc.scm
+++ b/ps-compiler/compile-gc.scm
@@ -13,6 +13,7 @@
 	     "../scheme/vm/gc-package-defs.scm")
 	   's48-heap-init
 	   "../scheme/vm/scheme48heap.c"
-	   '(header "#include \"scheme48vm.h\"")
+           '(header "#include <string.h>")
+           '(header "#include \"scheme48vm.h\"")
 	   ;'(copy (heap walk-over-type-in-area))
 	   '(integrate (real-copy-object s48-trace-locations!)))))
diff --git a/scsh/libscsh.c b/scsh/libscsh.c
index 2aa91d3..1aa2f41 100644
--- a/scsh/libscsh.c
+++ b/scsh/libscsh.c
@@ -4,6 +4,7 @@
 
 #include <stdarg.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include "scheme48.h"
 #include "libscsh.h"
 #include "sysdep.h"
diff --git a/scsh/scsh-tramp.c b/scsh/scsh-tramp.c
index b947fc6..b0a6c60 100644
--- a/scsh/scsh-tramp.c
+++ b/scsh/scsh-tramp.c
@@ -37,6 +37,7 @@
 
 #include <errno.h>
 #include <unistd.h>
+#include <stdlib.h> 
 
 #ifndef VM
 #define VM "/usr/local/lib/scsh/scshvm"
diff --git a/scsh/scsh_aux.c b/scsh/scsh_aux.c
index bcc54fc..e9387bd 100644
--- a/scsh/scsh_aux.c
+++ b/scsh/scsh_aux.c
@@ -3,7 +3,7 @@
 
 #include "scsh_aux.h"
 #include <signal.h>
-
+#include <stdio.h>
 
 int main(int argc, char* argv[]){
   int signr = atoi(argv[1]);