diff --git a/build/parseChangelog.c b/build/parseChangelog.c
index 65c0952a69..d8159a25a6 100644
--- a/build/parseChangelog.c
+++ b/build/parseChangelog.c
@@ -189,6 +189,39 @@ static int dateToTimet(const char * datestr, time_t * secs, int * date_words)
     return rc;
 }
 
+/*
+ * Ensure each changelog entry has a different, reproducable timestamp.
+ * We could ensure different at parse-time, but as the changelog is
+ * parsed newest first, creating reproducable stamps requires processing
+ * in the opposite order.
+ */
+static void monotonize(Header h)
+{
+    struct rpmtd_s td;
+
+    if (headerGet(h, RPMTAG_CHANGELOGTIME, &td, HEADERGET_ALLOC)) {
+	uint32_t *times = td.data;
+	uint32_t prevtime = 0;
+	int serial = 0;
+
+	for (int i = td.count; i >= 0; i--) {
+	    uint32_t t = times[i];
+	    if (prevtime) {
+		if (t == prevtime) {
+		    serial++;
+		    t += serial;
+		} else {
+		    serial = 0;
+		}
+	    }
+	    prevtime = times[i];
+	    times[i] = t;
+	}
+	headerMod(h, &td);
+	rpmtdFreeData(&td);
+    }
+}
+
 /**
  * Add %changelog section to header.
  * @param h		header
@@ -304,6 +337,8 @@ static rpmRC addChangelog(Header h, ARGV_const_t sb)
 	
 	s = next;
     }
+    monotonize(h);
+
     rc = RPMRC_OK;
 
 exit:
diff --git a/tests/Makefile.am b/tests/Makefile.am
index af10bb06fb..e5daa097ce 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -54,6 +54,7 @@ EXTRA_DIST += data/SPECS/hello-g3.spec
 EXTRA_DIST += data/SPECS/foo.spec
 EXTRA_DIST += data/SPECS/globtest.spec
 EXTRA_DIST += data/SPECS/versiontest.spec
+EXTRA_DIST += data/SPECS/chlog.spec
 EXTRA_DIST += data/SPECS/conflicttest.spec
 EXTRA_DIST += data/SPECS/configtest.spec
 EXTRA_DIST += data/SPECS/filedep.spec
diff --git a/tests/data/SPECS/chlog.spec b/tests/data/SPECS/chlog.spec
new file mode 100644
index 0000000000..a038b35c9f
--- /dev/null
+++ b/tests/data/SPECS/chlog.spec
@@ -0,0 +1,25 @@
+Name: chlog
+Summary: Testing changelog behavior
+Version: 1.2
+Release: 5
+License: GPL
+
+%description
+%{summary}
+
+%files
+
+%changelog
+* Tue Jan 19 2021 Tester <tester@example.com> - 1.2-5
+- Oh no not again
+* Mon Jan 18 2021 Tester <tester@example.com> - 1.2-4
+- This really isn't my day...
+* Mon Jan 18 2021 Tester <tester@example.com> - 1.2-3
+- Oh, it's Monday
+* Mon Jan 18 2021  <tester@example.com> - 1.2-2
+- Fixup one
+* Mon Jan 18 2021 Tester <tester@example.com> - 1.2-1
+- Rebase to 1.2
+* Sun Feb 02 2020 Tester <tester@example.com> - 1.0-1
+- Initial version
+
diff --git a/tests/rpmspec.at b/tests/rpmspec.at
index 2b11201dbf..025653c676 100644
--- a/tests/rpmspec.at
+++ b/tests/rpmspec.at
@@ -285,3 +285,31 @@ foo-bus = 1.0-1
 ],
 [])
 AT_CLEANUP
+
+AT_SETUP([rpmspec changelog])
+AT_KEYWORDS([rpmspec changelog])
+AT_CHECK([[
+runroot rpmspec -q --qf '[* %{CHANGELOGTIME:date} %{CHANGELOGNAME}\n%{CHANGELOGTEXT}\n\n]' /data/SPECS/chlog.spec
+]],
+[0],
+[* Tue Jan 19 12:00:00 2021 Tester <tester@example.com> - 1.2-5
+- Oh no not again
+
+* Mon Jan 18 12:00:03 2021 Tester <tester@example.com> - 1.2-4
+- This really isn't my day...
+
+* Mon Jan 18 12:00:02 2021 Tester <tester@example.com> - 1.2-3
+- Oh, it's Monday
+
+* Mon Jan 18 12:00:01 2021 <tester@example.com> - 1.2-2
+- Fixup one
+
+* Mon Jan 18 12:00:00 2021 Tester <tester@example.com> - 1.2-1
+- Rebase to 1.2
+
+* Sun Feb  2 12:00:00 2020 Tester <tester@example.com> - 1.0-1
+- Initial version
+
+],
+[])
+AT_CLEANUP