diff --git a/changes-entries/66182.txt b/changes-entries/66182.txt
new file mode 100644
index 00000000000..95112c102ee
--- /dev/null
+++ b/changes-entries/66182.txt
@@ -0,0 +1,3 @@
+  *) mod_autoindex: Fix a FancyIndexing listing sorted by last-modified
+     date (?C=M) showing 1970-01-01 for files modified before 1970,
+     instead of their real date. PR 66182 [Arturo Bernal]
diff --git a/modules/generators/mod_autoindex.c b/modules/generators/mod_autoindex.c
index 37bed118b06..a6ff4119b11 100644
--- a/modules/generators/mod_autoindex.c
+++ b/modules/generators/mod_autoindex.c
@@ -1416,14 +1416,9 @@ static struct ent *make_autoindex_entry(const apr_finfo_t *dirent,
     }
     ap_destroy_sub_req(rr);
     /*
-     * We don't need to take any special action for the file size key.
-     * If we did, it would go here.
+     * We don't need to take any special action for the file size or
+     * last-modified keys.  If we did, it would go here.
      */
-    if (keyid == K_LAST_MOD) {
-        if (p->lm < 0) {
-            p->lm = 0;
-        }
-    }
     return (p);
 }
 
diff --git a/test/modules/generators/test_002_autoindex.py b/test/modules/generators/test_002_autoindex.py
index 14d05bdc3f8..767f5f2abbb 100644
--- a/test/modules/generators/test_002_autoindex.py
+++ b/test/modules/generators/test_002_autoindex.py
@@ -1,9 +1,15 @@
+import calendar
+import os
 import textwrap
 
 import pytest
 
 from pyhttpd.conf import HttpdConf
 
+# A modification time before the 1970 epoch, to check that mod_autoindex
+# does not clamp it when sorting by last-modified (BZ 66182).
+OLD_MTIME = calendar.timegm((1958, 1, 1, 0, 0, 0, 0, 0, 0))
+
 
 class TestAutoindex:
 
@@ -17,11 +23,23 @@ def _class_scope(self, env):
                 Options +Indexes
                 IndexOptions FancyIndexing ScanHTMLTitles
             </Directory>
+            <Directory "{env.server_docs_dir}/autoindex/oldmtime">
+                Options +Indexes
+                IndexOptions FancyIndexing
+            </Directory>
             """),
         })
         conf.add_vhost(domains=[domain], port=env.http_port,
                        doc_root="htdocs/autoindex")
         conf.install()
+
+        oldmtime_dir = os.path.join(env.server_docs_dir, "autoindex", "oldmtime")
+        os.makedirs(oldmtime_dir, exist_ok=True)
+        oldfile = os.path.join(oldmtime_dir, "oldfile.txt")
+        with open(oldfile, "w") as f:
+            f.write("old file\n")
+        os.utime(oldfile, (OLD_MTIME, OLD_MTIME))
+
         assert env.apache_restart() == 0
 
     def test_generators_002_01_scan_title_bare_amp(self, env):
@@ -32,3 +50,22 @@ def test_generators_002_01_scan_title_bare_amp(self, env):
         r = env.curl_get(env.mkurl("http", "autoindex", "/listing/"))
         assert r.response["status"] == 200
         assert "AT&T" in r.response["body"].decode()
+
+    def test_generators_002_02_old_mtime_not_clamped_when_sorted(self, env):
+        """A file modified before 1970 keeps its real date when the listing
+        is explicitly sorted by last-modified (?C=M). Before the fix,
+        make_autoindex_entry() clamped any negative apr_time_t to 0 when
+        keyid == K_LAST_MOD, displaying 1970-01-01 instead of the real
+        1958 date -- even though the unsorted, default-order listing (which
+        does not hit that code path) already showed it correctly."""
+        unsorted = env.curl_get(env.mkurl("http", "autoindex", "/oldmtime/"))
+        assert unsorted.response["status"] == 200
+        unsorted_body = unsorted.response["body"].decode()
+        assert "1958-01-01" in unsorted_body
+
+        sorted_by_date = env.curl_get(
+            env.mkurl("http", "autoindex", "/oldmtime/?C=M;O=A"))
+        assert sorted_by_date.response["status"] == 200
+        sorted_body = sorted_by_date.response["body"].decode()
+        assert "1958-01-01" in sorted_body
+        assert "1970-01-01" not in sorted_body