diff --git a/dis.h b/dis.h
index c48a6c2..91dfcb9 100644
--- a/dis.h
+++ b/dis.h
@@ -20,6 +20,8 @@
  */
 
 
+#include <stddef.h>
+
 extern bool sevenbit;  /* if true, mask character data with 0x7f
 			 to ignore MSB */
 
@@ -124,10 +126,10 @@ char *get_name(addr_t loc);
 #define OFS 267
 
 extern FILE *yyin, *yyout;
-int lineno;
+extern int lineno;
 
 int yywrap(), yyerror();
-char *emalloc();
+void *emalloc (size_t n);
 
 typedef union  {
 	int ival;
diff --git a/lex.l b/lex.l
index 3c637c6..e8bb8e2 100644
--- a/lex.l
+++ b/lex.l
@@ -23,15 +23,15 @@
 %{
 #undef ECHO
 #include <stdbool.h>
+#include <stddef.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include "dis.h"
 int lineno = 0;
-char *strcpy();
 %}
 
-%option nounput
+%option noinput nounput
 
 digit		[0-9]
 hexdigit	[0-9a-fA-F]
@@ -75,7 +75,7 @@ alphanum	[0-9a-zA-Z_]
 			}
 
 {alpha}{alphanum}*	{
-			  token.sval = emalloc((unsigned) strlen(yytext)+1);
+			  token.sval = emalloc(strlen(yytext)+1);
 			  (void)strcpy((char *)token.sval, (char *)yytext);
 			  return NAME;
 			}
@@ -90,13 +90,12 @@ alphanum	[0-9a-zA-Z_]
 
 %%
 
-char *
-emalloc(n)
-unsigned n;
+void *
+emalloc(size_t n)
 {
-	char *ptr;
+	void *ptr;
 
-	if ((ptr = malloc(n)) == (char *) 0) {
+	if ((ptr = malloc(n)) == NULL) {
 		(void) fprintf(stderr,"out of core");
 		exit(1);
 	}
diff --git a/main.c b/main.c
index a6f101d..d440162 100644
--- a/main.c
+++ b/main.c
@@ -90,7 +90,7 @@ void trace_inst (addr_t addr)
 {
   int opcode;
   register struct info *ip; 
-  int operand;
+  int operand = 0;
   int istart;
 
   for (;;)
@@ -116,7 +116,6 @@ void trace_inst (addr_t addr)
       switch(ip->nb)
 	{
 	case 1:
-	  operand = 0;  /* only to avoid "may be used unitialized" warning */
 	  break;
 	case 2:
 	  operand = getbyte(addr);
@@ -232,7 +231,7 @@ void do_ptrace (void)
 {
   for (int i = 0; i<tstarti; i++)
     {
-      char *trace_sym = (char *) malloc (6);
+      char *trace_sym = emalloc (6);
       sprintf (trace_sym, "P%04x", tstart [i]);
       start_trace(tstart[i], trace_sym);
     }
@@ -246,7 +245,7 @@ void do_rtstab (void)
       int loc = rtstab_addr [i];
       for (int j = 0; j < rtstab_size [i]; j++)
 	{
-	  char *trace_sym = (char *) malloc (6);
+	  char *trace_sym = emalloc (6);
 	  int code = d [loc] + (d [loc + 1] << 8) + 1;
 	  sprintf (trace_sym, "T%04x", code);
 	  start_trace (code, trace_sym);
@@ -262,7 +261,7 @@ void do_jtab (void)
       int loc = jtab_addr [i];
       for (int j = 0; j < jtab_size [i]; j++)
 	{
-	  char *trace_sym = (char *) malloc (6);
+	  char *trace_sym = emalloc (6);
 	  int code = d [loc] + (d [loc + 1] << 8);
 	  sprintf (trace_sym, "T%04x", code);
 	  start_trace (code, trace_sym);
@@ -279,7 +278,7 @@ void do_jtab2 (void)
       int loc_h = jtab2_addr_high [i];
       for (int j = 0; j < jtab2_size [i]; j++)
 	{
-	  char *trace_sym = (char *) malloc (6);
+	  char *trace_sym = emalloc (6);
 	  int code = d [loc_l + j] + (d [loc_h + j] << 8);
 	  sprintf (trace_sym, "T%04x", code);
 	  start_trace (code, trace_sym);
@@ -511,6 +510,8 @@ void loadboot (void)
 	if (fread((char *)&d[base_addr], 1, len, fp) != len) 
 		crash("input too short");
 
+	fclose(fp);
+
 	for(int i = base_addr; len > 0; len--) 
 		f[i++] |= LOADED;
 
@@ -544,6 +545,7 @@ void loadfile (void)
 				i = getword(RUNLOC);
 				start_trace(i, "**RUN**");
 			}
+			fclose(fp);
 			return;
 		}
 
@@ -608,6 +610,8 @@ void c64loadfile (void)
 		f[i++] |= LOADED;
 		}
 
+	fclose(fp);
+
 	start_trace(base_addr, "**C64BIN**");
 }
 
@@ -637,6 +641,8 @@ void binaryloadfile (void)
       f [i++] |= LOADED;
     }
 
+  fclose(fp);
+
   reset = vector_address - 4;
   irq = vector_address - 2;
   nmi = vector_address - 6;
@@ -647,7 +653,7 @@ void binaryloadfile (void)
     {
       for (int j = 0; j < entry_count; j++)
 	{
-	  char *label = malloc(7);
+	  char *label = emalloc (7);
 	  sprintf (label, "e_%04x", entry_address[j]);
 	  printf("label: %s\n", label);
 	  start_trace (entry_address[j], label);
diff --git a/print.c b/print.c
index 1a3f25c..17657a8 100644
--- a/print.c
+++ b/print.c
@@ -31,20 +31,17 @@
 
 #include "dis.h"
 
-char *strcpy();
-char *strcat();
-
 
 static char *lname (addr_t i, int offset_ok)
 {
-	static char buf[20];
+	static char buf[40];  /* ~6-char label, +/-, long int */
 	char t;
 
 	if (f[i] & NAMED) 
 		return(get_name(i));
 	if (f[i] & OFFSET) {
-		(void)strcpy(buf, get_name(i+offset[i]));
-		sprintf (buf + strlen (buf), "%c%ld",
+		sprintf (buf, "%s%c%ld",
+			 get_name(i+offset[i]),
 			 (offset [i] <= 0) ? '+' : '-',
 			 labs (offset [i]));
 		return (buf);
@@ -168,7 +165,7 @@ int print_inst(addr_t addr)
 {
 	int opcode;
 	register struct info *ip; 
-	int operand;
+	int operand = 0;
 
 	opcode = getbyte(addr);
 	ip = &optbl[opcode];
@@ -179,8 +176,6 @@ int print_inst(addr_t addr)
 
 	switch(ip->nb) {
 		case 1:
-			operand = 0;  /* only to avoid "may be used
-					 unitialized" warning */
 			break;
 		case 2:
 			operand = getbyte(addr);
diff --git a/ref.c b/ref.c
index 5a40156..134f9b2 100644
--- a/ref.c
+++ b/ref.c
@@ -71,7 +71,7 @@ void save_ref (addr_t refer, addr_t refee)
 	struct ref_chain *rc;
 	struct hashslot *hp;
 
-	rc = (struct ref_chain *)emalloc(sizeof(*rc));
+	rc = emalloc(sizeof(*rc));
 	rc->who = refer;
 	hp = hash(refee, 1);
 	rc->next = hp->ref;