--- a/kcc.c
+++ b/kcc.c
@@ -134,7 +134,11 @@
 extern unsigned short hiragana[];
 unsigned short *kanatbl = katakana;
 
+#ifdef __STDC__
+void error(char *format, ...);
+#else
 void error();
+#endif
 
 /**********************************************************************
  *                                                                    *
@@ -364,14 +368,30 @@
     NAME
 	error - print formatted error message on stderr and die
  ---------------------------------------------------------------------*/
+#ifdef __STDC__
+#include <stdarg.h>
+#else
 #include <varargs.h>
+#endif
 
-void error(va_alist)
-    va_dcl
+void
+#ifdef __STDC__
+error(char *format, ...)
+#else
+error(va_alist) va_dcl
+#endif
 {
     va_list args;
 
+#ifdef __STDC__
+    va_start(args, format);
+#else
+    char *format;
+
     va_start(args);
+    /* extract the fixed argument */
+    format = va_arg(args, char *);
+#endif
     fprintf(stderr, "%s: ", progname);
     vfprintf(stderr, va_arg(args, char *), args);
     putc('\n', stderr);