diff --git a/modules/src/alloc/Malloc.c b/modules/src/alloc/Malloc.c
index 29951d013..156f117fa 100644
--- a/modules/src/alloc/Malloc.c
+++ b/modules/src/alloc/Malloc.c
@@ -10,6 +10,11 @@
 	char *Malloc(n)		: allocate n bytes
 */
 
+#if __STDC__
+#include <stdlib.h>
+#else
+extern char *malloc();
+#endif
 #include	"alloc.h"
 
 char *
diff --git a/modules/src/alloc/No_Mem.c b/modules/src/alloc/No_Mem.c
index 3a0155b59..c880881df 100644
--- a/modules/src/alloc/No_Mem.c
+++ b/modules/src/alloc/No_Mem.c
@@ -4,6 +4,7 @@
  * See the copyright notice in the ACK home directory, in the file "Copyright".
  */
 #include	<system.h>
+#include	"alloc.h"
 
 No_Mem()
 {
diff --git a/modules/src/alloc/Realloc.c b/modules/src/alloc/Realloc.c
index 76e24d9e7..e40af1b11 100644
--- a/modules/src/alloc/Realloc.c
+++ b/modules/src/alloc/Realloc.c
@@ -10,6 +10,13 @@
 	char *Realloc(ptr, n)	: reallocate buffer to n bytes
 */
 
+#if __STDC__
+#include <stdlib.h>
+#else
+extern char *malloc();
+extern char *realloc();
+#endif
+
 #include	"alloc.h"
 
 char *
diff --git a/modules/src/alloc/Salloc.c b/modules/src/alloc/Salloc.c
index 4d16045c2..ba7f074d9 100644
--- a/modules/src/alloc/Salloc.c
+++ b/modules/src/alloc/Salloc.c
@@ -11,6 +11,12 @@
 					str
 */
 
+#if __STDC__
+#include <stdlib.h>
+#else
+extern char *malloc();
+#endif
+
 #include	"alloc.h"
 
 char *
diff --git a/modules/src/alloc/alloc.h b/modules/src/alloc/alloc.h
index 966aaf8ce..82783a2d9 100644
--- a/modules/src/alloc/alloc.h
+++ b/modules/src/alloc/alloc.h
@@ -17,11 +17,19 @@
 		char *Srealloc(str, n)	same as Realloc.
 */
 
-extern char *Salloc(), *Malloc(), *Srealloc(), *Realloc();
 #if __STDC__
-extern void *malloc(), *realloc();
+char *Malloc(unsigned int);
+char *Salloc(char *, unsigned int);
+char *Srealloc(char *, unsigned int);
+char *Realloc(char *, unsigned int);
+char *st_alloc(char **, unsigned int, int);
+char *std_alloc(char **, unsigned int, int, int *);
+int No_Mem(void);
+void clear(char *, unsigned int);
+void botch(char *, unsigned int);
 #else
-extern char *malloc(), *realloc();
+extern char	*Salloc(), *Malloc(), *Srealloc(), *Realloc();
+extern char	*st_alloc(), *std_alloc();
 #endif
 
 /*	S T R U C T U R E - S T O R A G E  D E F I N I T I O N S	*/
@@ -30,7 +38,6 @@ typedef struct _ALLOC_ {
 	struct _ALLOC_ *_A_next;
 } *_PALLOC_;
 
-extern char	*st_alloc();
 
 #define	_A_st_free(ptr, phead, size)	(((_PALLOC_)ptr)->_A_next = \
 						(_PALLOC_)(*phead), \
diff --git a/modules/src/alloc/botch.c b/modules/src/alloc/botch.c
index 410da9358..cc5880866 100644
--- a/modules/src/alloc/botch.c
+++ b/modules/src/alloc/botch.c
@@ -7,6 +7,11 @@
 		to check if freed memory is used inappopriately.
 */
 
+#include "alloc.h"
+
+#if __STDC__
+void
+#endif
 botch(ptr, n)
 	register char *ptr;
 	register unsigned int n;
diff --git a/modules/src/alloc/clear.c b/modules/src/alloc/clear.c
index 996af5343..36ebcad59 100644
--- a/modules/src/alloc/clear.c
+++ b/modules/src/alloc/clear.c
@@ -6,7 +6,13 @@
 /*	clear - clear a block of memory, and try to do it fast.
 */
 
+#include "alloc.h"
+
 /* instead of Calloc: */
+
+#if __STDC__
+void
+#endif
 clear(ptr, n)
 	register char *ptr;
 	register unsigned int n;
diff --git a/modules/src/alloc/st_alloc.c b/modules/src/alloc/st_alloc.c
index ad469dff8..404d95c33 100644
--- a/modules/src/alloc/st_alloc.c
+++ b/modules/src/alloc/st_alloc.c
@@ -8,6 +8,12 @@
 		The counterpart, st_free, is a macro, defined in alloc.h
 */
 
+#if __STDC__
+#include <stdlib.h>
+#else
+extern char *malloc();
+#endif
+
 #include	"alloc.h"
 
 char *
diff --git a/modules/src/alloc/std_alloc.c b/modules/src/alloc/std_alloc.c
index ada36f2cb..5335cf0ee 100644
--- a/modules/src/alloc/std_alloc.c
+++ b/modules/src/alloc/std_alloc.c
@@ -9,6 +9,12 @@
 	This is a counting version of st_alloc.
 */
 
+#if __STDC__
+#include <stdlib.h>
+#else
+extern char *malloc();
+#endif
+
 #include	"alloc.h"
 
 char *