diff --git a/test-linuxcnc-source-link.sh b/test-linuxcnc-source-link.sh
index 4047255..f6883a8 100755
--- a/test-linuxcnc-source-link.sh
+++ b/test-linuxcnc-source-link.sh
@@ -236,6 +236,12 @@ INI_FILE_NAME="$multi_spindle_modes_file" CNC_SIM_RS274_VAR="$var_file" \
 CNC_SIM_RS274_VAR="$var_file" \
     "$build_dir/linuxcnc_rs274_source_dump" tests/gcode/linuxcnc_spindle_orient.ngc \
     >"$output_dir/cnc_sim_linuxcnc_source_spindle_orient.json"
+# Source basis: LinuxCNC src/emc/rs274ngc/rs274ngc_pre.cc init reads
+# [TRAJ] SPINDLES from INI_FILE_NAME, and interp_convert.cc routes M19 with a
+# $ selector to the selected spindle for orient and wait Canon calls.
+INI_FILE_NAME="$multi_spindle_modes_file" CNC_SIM_RS274_VAR="$var_file" \
+    "$build_dir/linuxcnc_rs274_source_dump" tests/gcode/linuxcnc_multi_spindle_orient.ngc \
+    >"$output_dir/cnc_sim_linuxcnc_source_multi_spindle_orient.json"
 CNC_SIM_RS274_VAR="$var_file" \
     "$build_dir/linuxcnc_rs274_source_dump" tests/gcode/linuxcnc_io_controls.ngc \
     >"$output_dir/cnc_sim_linuxcnc_source_io_controls.json"
@@ -1899,6 +1905,27 @@ if not any(
 ):
     raise SystemExit("missing source-linked M19 spindle orient wait state")
 
+multi_spindle_orient = json.loads((OUTPUT_DIR / "cnc_sim_linuxcnc_source_multi_spindle_orient.json").read_text())
+if not any(
+    event["type"] == "comment" and
+    event["line"] == 4 and
+    event["reserved"] == 1901 and
+    event["tool"] == 1 and
+    event["feed"] == 45 and
+    event["arcTurns"] == 1
+    for event in multi_spindle_orient
+):
+    raise SystemExit("missing source-linked selected-spindle M19 orient state")
+if not any(
+    event["type"] == "comment" and
+    event["line"] == 4 and
+    event["reserved"] == 1902 and
+    event["tool"] == 1 and
+    event["dwellSeconds"] == 2
+    for event in multi_spindle_orient
+):
+    raise SystemExit("missing source-linked selected-spindle M19 orient wait state")
+
 io_controls = json.loads((OUTPUT_DIR / "cnc_sim_linuxcnc_source_io_controls.json").read_text())
 io_states = [
     (event["line"], event["reserved"], event["tool"], event["feed"], event["arcTurns"], event["dwellSeconds"])
@@ -3713,6 +3740,7 @@ echo "dumped $output_dir/cnc_sim_linuxcnc_source_multi_spindle_direction.json"
 echo "dumped $output_dir/cnc_sim_linuxcnc_source_multi_spindle_all_direction.json"
 echo "dumped $output_dir/cnc_sim_linuxcnc_source_spindle_modes.json"
 echo "dumped $output_dir/cnc_sim_linuxcnc_source_spindle_orient.json"
+echo "dumped $output_dir/cnc_sim_linuxcnc_source_multi_spindle_orient.json"
 echo "dumped $output_dir/cnc_sim_linuxcnc_source_io_controls.json"
 echo "dumped $output_dir/cnc_sim_linuxcnc_source_override_controls.json"
 echo "dumped $output_dir/cnc_sim_linuxcnc_source_modal_state.json"
diff --git a/tests/gcode/linuxcnc_multi_spindle_orient.ngc b/tests/gcode/linuxcnc_multi_spindle_orient.ngc
new file mode 100644
index 0000000..6e53b99
--- /dev/null
+++ b/tests/gcode/linuxcnc_multi_spindle_orient.ngc
@@ -0,0 +1,5 @@
+G21 G90 G17
+(Source basis: LinuxCNC src/emc/rs274ngc/rs274ngc_pre.cc init reads [TRAJ] SPINDLES from INI_FILE_NAME.)
+(Source basis: LinuxCNC src/emc/rs274ngc/interp_convert.cc M19 with $ selects spindle orient and wait calls.)
+M19 R45 P1 Q2 $1
+M30