diff --git a/lang/basic/src.old/initialize.c b/lang/basic/src.old/initialize.c
index 9a6e4851..12a79912 100644
--- a/lang/basic/src.old/initialize.c
+++ b/lang/basic/src.old/initialize.c
@@ -13,8 +13,25 @@ FILE	*datfile;
 
 initialize()
 {
+	register char *cindex, *cptr ;
+
 	sprintf(tmpfname,"%s/abc%d",TMP_DIR,getpid());
-	strcpy(datfname,program);
+	/* Find the basename */
+	/* Strip leading directories */
+	cindex= (char *)0 ;
+	for ( cptr=program ; *cptr ; cptr++ ) if ( *cptr=='/' ) cindex=cptr ;
+	if ( !cindex ) cindex= program ;
+	else {
+		cindex++ ;
+		if ( !*cindex ) {
+			warning("Null program name, assuming \"basic\"") ;
+			cindex= "basic" ;
+		}
+	}
+	cptr=datfname ;
+	while ( *cptr++ = *cindex++ ) ;
+	/* Strip trailing suffix */
+	if ( cptr>datfname+3 && cptr[-3]=='.' ) cptr[-3]=0 ;
 	strcat(datfname,".d");
 	yyin= fopen(inpfile,"r");
 	emfile= fopen(outfile,"w");