diff --git a/library/term_io.m b/library/term_io.m
index 420fd6656..15fa9b4f1 100644
--- a/library/term_io.m
+++ b/library/term_io.m
@@ -2,7 +2,7 @@
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
 % Copyright (C) 1994-2006, 2009, 2011-2012 The University of Melbourne.
-% Copyright (C) 2014-2025 The Mercury team.
+% Copyright (C) 2014-2026 The Mercury team.
 % This file is distributed under the terms specified in COPYING.LIB.
 %---------------------------------------------------------------------------%
 %
@@ -494,7 +494,7 @@ write_term_nl(OutStream, VarSet, Term, !IO) :-
 
 format_term_nl(Stream, VarSet, Term, !State) :-
     OpTable = init_mercury_op_table,
-    format_term_with_op_table(Stream, OpTable, VarSet, Term, !State).
+    format_term_nl_with_op_table(Stream, OpTable, VarSet, Term, !State).
 
 %---------------------%
 
diff --git a/tests/hard_coded/Mmakefile b/tests/hard_coded/Mmakefile
index 7de674c8b..34ae53c32 100644
--- a/tests/hard_coded/Mmakefile
+++ b/tests/hard_coded/Mmakefile
@@ -170,6 +170,7 @@ ORDINARY_PROGS = \
 	foreign_type_1 \
 	foreign_type_2 \
 	foreign_type_3 \
+	format_term_nl \
 	frameopt_pragma_redirect \
 	free_free_mode \
 	from_ground_term_bug \
diff --git a/tests/hard_coded/format_term_nl.exp b/tests/hard_coded/format_term_nl.exp
new file mode 100644
index 000000000..53cdf1e93
--- /dev/null
+++ b/tests/hard_coded/format_term_nl.exp
@@ -0,0 +1 @@
+PASSED
diff --git a/tests/hard_coded/format_term_nl.m b/tests/hard_coded/format_term_nl.m
new file mode 100644
index 000000000..17f08d177
--- /dev/null
+++ b/tests/hard_coded/format_term_nl.m
@@ -0,0 +1,56 @@
+%---------------------------------------------------------------------------%
+% vim: ft=mercury ts=4 sw=4 et
+%---------------------------------------------------------------------------%
+% Regression test for bug with term_io.format_term_nl/5 in rotd-2026-02-19
+% and before where the terminating ".\n" was not being appended to the term.
+%---------------------------------------------------------------------------%
+
+:- module format_term_nl.
+:- interface.
+
+:- import_module io.
+
+:- pred main(io::di, io::uo) is det.
+
+%---------------------------------------------------------------------------%
+%---------------------------------------------------------------------------%
+
+:- implementation.
+
+:- import_module bool.
+:- import_module integer.
+:- import_module list.
+:- import_module string.
+:- import_module string.builder.
+:- import_module term.
+:- import_module term_context.
+:- import_module term_int.
+:- import_module term_io.
+:- import_module varset.
+
+%---------------------------------------------------------------------------%
+
+main(!IO) :-
+    varset.init(VarSet : varset(generic)),
+    Args = [
+        term.functor(term.atom("bar"), [], dummy_context),
+        term_int.int_to_decimal_term(42, dummy_context)
+    ],
+    Term = term.functor(term.atom("foo"), Args, dummy_context),
+
+    State0 = string.builder.init,
+    term_io.format_term_nl(string.builder.handle, VarSet, Term,
+        State0, State),
+    String = string.builder.to_string(State),
+
+    ( if string.suffix(String, ".\n") then
+        io.print_line("PASSED", !IO)
+    else
+        io.print_line("FAILED", !IO),
+        io.print_line(String, !IO),
+        io.nl(!IO)
+    ).
+
+%---------------------------------------------------------------------------%
+:- end_module format_term_nl.
+%---------------------------------------------------------------------------%