diff --git a/src/mccode_antlr/translators/c_trace.py b/src/mccode_antlr/translators/c_trace.py
index 15a3eae..905fbcb 100644
--- a/src/mccode_antlr/translators/c_trace.py
+++ b/src/mccode_antlr/translators/c_trace.py
@@ -8,7 +8,7 @@ def _runtime_parameters(flavor: Flavor):
     if Flavor.MCSTAS == flavor:
         pars.extend(['vx', 'vy', 'vz', 't', 'sx', 'sy', 'sz', 'p', 'mcgravitation', 'mcMagnet', 'allow_backprop'])
     elif Flavor.MCXTRACE == flavor:
-        pars.extend(['kx', 'ky', 'kz', 'phi', 't', 'Ex', 'Ey', 'Ez', 'p'])
+        pars.extend(['kx', 'ky', 'kz', 'phi', 't', 'Ex', 'Ey', 'Ez', 'p', 'allow_backprop'])
     else:
         raise ValueError(f'Unknown flavor {flavor}')
     # Add the temporary particle parameters added sometime after v3.4.0 ... to the v3.4.0 tag
diff --git a/tests/test_trace_allow_backprop.py b/tests/test_trace_allow_backprop.py
new file mode 100644
index 0000000..842d952
--- /dev/null
+++ b/tests/test_trace_allow_backprop.py
@@ -0,0 +1,10 @@
+from mccode_antlr import Flavor
+from mccode_antlr.translators.c_trace import def_trace_section, undef_trace_section
+
+
+def test_allow_backprop_defined_in_trace():
+    # The runtime macros (PROP_*, DISALLOW_BACKPROP) use `allow_backprop` for both
+    # flavors, McXtrace since McCode v3.6.9 -- see mccode-dev/mccode-antlr#118
+    for flavor in (Flavor.MCSTAS, Flavor.MCXTRACE):
+        assert '#define allow_backprop (_particle->allow_backprop)' in def_trace_section(flavor)
+        assert '#undef allow_backprop' in undef_trace_section(flavor)