diff --git a/src/files.c b/src/files.c
index 4e442e094..8c69e9399 100644
--- a/src/files.c
+++ b/src/files.c
@@ -1,4 +1,4 @@
-/* NetHack 3.7	files.c	$NHDT-Date: 1711213887 2024/03/23 17:11:27 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.397 $ */
+/* NetHack 3.7	files.c	$NHDT-Date: 1717449127 2024/06/03 21:12:07 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.399 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Derek S. Ray, 2015. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -2796,10 +2796,9 @@ cnf_line_EXPLORERS(char *bufp)
 staticfn boolean
 cnf_line_DEBUGFILES(char *bufp)
 {
-    /* if showdebug() has already been called (perhaps we've added
-       some debugpline() calls to option processing) and has found
-       a value for getenv("DEBUGFILES"), don't override that */
-    if (sysopt.env_dbgfl <= 0) {
+    /* might already have a vaule from getenv("DEBUGFILES");
+       if so, ignore this value from SYSCF */
+    if (!sysopt.env_dbgfl) {
         if (sysopt.debugfiles)
             free((genericptr_t) sysopt.debugfiles);
         sysopt.debugfiles = dupstr(bufp);
@@ -4523,20 +4522,6 @@ debugcore(const char *filename, boolean wildcards)
     if (!filename || !*filename)
         return FALSE; /* sanity precaution */
 
-    if (sysopt.env_dbgfl == 0) {
-        /* check once for DEBUGFILES in the environment;
-           if found, it supersedes the sysconf value
-           [note: getenv() rather than nh_getenv() since a long value
-           is valid and doesn't pose any sort of overflow risk here] */
-        if ((p = getenv("DEBUGFILES")) != 0) {
-            if (sysopt.debugfiles)
-                free((genericptr_t) sysopt.debugfiles);
-            sysopt.debugfiles = dupstr(p);
-            sysopt.env_dbgfl = 1;
-        } else
-            sysopt.env_dbgfl = -1;
-    }
-
     debugfiles = sysopt.debugfiles;
     /* usual case: sysopt.debugfiles will be empty */
     if (!debugfiles || !*debugfiles)
diff --git a/src/sys.c b/src/sys.c
index 7f463c50d..ad2274fbe 100644
--- a/src/sys.c
+++ b/src/sys.c
@@ -1,4 +1,4 @@
-/* NetHack 3.7	sys.c	$NHDT-Date: 1693083254 2023/08/26 20:54:14 $  $NHDT-Branch: keni-crashweb2 $:$NHDT-Revision: 1.63 $ */
+/* NetHack 3.7	sys.c	$NHDT-Date: 1717449153 2024/06/03 21:12:33 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.64 $ */
 /* Copyright (c) Kenneth Lorber, Kensington, Maryland, 2008. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -20,6 +20,8 @@ struct sysopt sysopt;
 void
 sys_early_init(void)
 {
+    const char *p;
+
     sysopt.support = (char *) 0;
     sysopt.recover = (char *) 0;
 #ifdef SYSCF
@@ -27,15 +29,22 @@ sys_early_init(void)
 #else
     sysopt.wizards = dupstr(WIZARD_NAME);
 #endif
+
+    if ((p = getenv("DEBUGFILES")) != 0) {
+        sysopt.debugfiles = dupstr(p);
+        sysopt.env_dbgfl = 1; /* prevent sysconf processing from overriding */
+    } else {
 #if defined(SYSCF) || !defined(DEBUGFILES)
-    sysopt.debugfiles = (char *) 0;
+        sysopt.debugfiles = (char *) 0;
 #else
-    sysopt.debugfiles = dupstr(DEBUGFILES);
+        sysopt.debugfiles = dupstr(DEBUGFILES);
 #endif
+        sysopt.env_dbgfl = 0;
+    }
+
 #ifdef DUMPLOG
     sysopt.dumplogfile = (char *) 0;
 #endif
-    sysopt.env_dbgfl = 0; /* haven't checked getenv("DEBUGFILES") yet */
     sysopt.shellers = (char *) 0;
     sysopt.explorers = (char *) 0;
     sysopt.genericusers = (char *) 0;
@@ -105,6 +114,7 @@ sysopt_release(void)
     if (sysopt.debugfiles)
         free((genericptr_t) sysopt.debugfiles),
         sysopt.debugfiles = (char *) 0;
+    sysopt.env_dbgfl = 0;
 #ifdef DUMPLOG
     if (sysopt.dumplogfile)
         free((genericptr_t) sysopt.dumplogfile), sysopt.dumplogfile=(char *) 0;