diff --git a/docs/PORTMASTER.md b/docs/PORTMASTER.md
index fceea29..91c8457 100644
--- a/docs/PORTMASTER.md
+++ b/docs/PORTMASTER.md
@@ -32,9 +32,10 @@ directory. The templates in `scripts/portmaster/` are authoritative.
 - The executable is `netfishing/NETfishing.aarch64`.
 - The package declares AArch64, two analog sticks, GLIBC 2.28, and
   `weston_pkg_0.2.squashfs`.
-- The launcher starts GPTOKEYB in exit-only mode without a `-c` mapping file.
-  PortMaster therefore owns only its device-specific force-quit chord while
-  Godot and NETfishing's controller mapping manager handle gameplay input.
+- The launcher starts GPTOKEYB with the explicit `netfishing.gptk` no-op map.
+  Every keyboard and mouse binding is disabled, leaving only PortMaster's
+  device-specific force-quit chord while Godot and NETfishing's controller
+  mapping manager handle gameplay input.
 - The launcher calls `pm_platform_helper` for the game executable after
   starting GPTOKEYB and calls `pm_finish` after the game exits.
 - Persistent device data remains under `netfishing/conf/data`,
@@ -98,7 +99,7 @@ Before upgrading an existing installation, preserve
 
 1. Confirm the installed executable and PCK hashes match the staged release.
 2. Confirm the installed launcher contains the canonical PortMaster header,
-   starts GPTOKEYB without a `-c` mapping file, and calls
+   starts GPTOKEYB with `netfishing.gptk`, and calls
    `pm_platform_helper` for the game executable.
 3. Confirm `conf/` was not replaced or removed.
 4. Launch the installed port through the normal muOS menu.
@@ -160,10 +161,12 @@ failure with the `GO-Super Gamepad` mapping. Export the single selected
 `westonwrap.sh`, so Weston and the game inherit it without tokenizing the
 mapping text.
 
-Do not pass a `.gptk` controller mapping to GPTOKEYB. Its exit-only process
-must retain PortMaster's controller configuration, while the verified Godot
-mapping remains scoped to the game command. This prevents duplicate or
-translated gameplay events while preserving the system force-quit chord.
+Legacy GPTOKEYB builds can load their compiled default keyboard map when no
+`-c` file is supplied. That map translates face buttons, D-pad directions, and
+sticks into keyboard or mouse events on top of Godot's native controller input.
+Always pass `netfishing.gptk`, which explicitly unassigns every direct and
+hotkey binding with GPTOKEYB's `\"` value. Do not add gameplay mappings to this
+file. The Start+Select kill chord remains independent of the no-op bindings.
 
 Do not call `Input.add_joy_mapping(..., true)` for a recognized connected muOS
 controller. Updating this virtual controller after connection can stop Godot
diff --git a/scripts/build_portmaster.sh b/scripts/build_portmaster.sh
index 908c185..752fe9d 100755
--- a/scripts/build_portmaster.sh
+++ b/scripts/build_portmaster.sh
@@ -115,6 +115,8 @@ mkdir -p -- "${GAME_ROOT}/licenses"
 
 install -m 0755 "${TEMPLATE_ROOT}/NETfishing.sh" "${STAGE_ROOT}/NETfishing.sh"
 install -m 0644 "${TEMPLATE_ROOT}/port.json" "${GAME_ROOT}/port.json"
+install -m 0644 "${TEMPLATE_ROOT}/netfishing.gptk" \
+  "${GAME_ROOT}/netfishing.gptk"
 install -m 0755 "${ARM64_EXECUTABLE}" "${GAME_ROOT}/NETfishing.aarch64"
 install -m 0644 "${ARM64_PCK}" "${GAME_ROOT}/NETfishing.pck"
 install -m 0644 "${TEMPLATE_ROOT}/gameinfo.xml" "${GAME_ROOT}/gameinfo.xml"
@@ -230,7 +232,9 @@ if [[ -z "${CONTROLLER_ENV_LINE}" || -z "${WESTON_LAUNCH_LINE}" || \
   echo "SDL_GAMECONTROLLERCONFIG must be exported before westonwrap.sh." >&2
   exit 1
 fi
-grep -Fq '$GPTOKEYB "NETfishing.aarch64" &' \
+grep -Fq 'GPTOKEYB_CONFIG="$GAMEDIR/netfishing.gptk"' \
+  "${STAGE_ROOT}/NETfishing.sh"
+grep -Fq '$GPTOKEYB "NETfishing.aarch64" -c "$GPTOKEYB_CONFIG" &' \
   "${STAGE_ROOT}/NETfishing.sh"
 grep -Fq 'pm_platform_helper "$GAME_EXECUTABLE"' \
   "${STAGE_ROOT}/NETfishing.sh"
@@ -240,9 +244,25 @@ if [[ "$(grep -Ec '^[[:space:]]*\$GPTOKEYB[[:space:]]' \
   echo "NETfishing must start exactly one GPTOKEYB exit handler." >&2
   exit 1
 fi
-if grep -Eq '\$GPTOKEYB.*[[:space:]]-c([[:space:]]|$)' \
-  "${STAGE_ROOT}/NETfishing.sh"; then
-  echo "GPTOKEYB controller mappings must not be enabled for NETfishing." >&2
+readonly GPTOKEYB_NOOP_KEYS=(
+  back guide start
+  a a_hk b b_hk x x_hk y y_hk
+  l1 l1_hk l2 l2_hk l3 r1 r1_hk r2 r2_hk r3
+  up down left right
+  left_analog_up left_analog_down left_analog_left left_analog_right
+  right_analog_up right_analog_down right_analog_left right_analog_right
+)
+for noop_key in "${GPTOKEYB_NOOP_KEYS[@]}"; do
+  if ! grep -Eq \
+    "^[[:space:]]*${noop_key}[[:space:]]*=[[:space:]]*\\\\\"[[:space:]]*$" \
+    "${GAME_ROOT}/netfishing.gptk"; then
+    echo "GPTOKEYB no-op mapping is missing: ${noop_key}" >&2
+    exit 1
+  fi
+done
+if [[ "$(grep -Ec '^[[:space:]]*[a-z0-9_]+[[:space:]]*=' \
+  "${GAME_ROOT}/netfishing.gptk")" -ne "${#GPTOKEYB_NOOP_KEYS[@]}" ]]; then
+  echo "GPTOKEYB no-op mapping contains an unexpected assignment." >&2
   exit 1
 fi
 if unzip -Z1 "${ARCHIVE}" | grep -E \
diff --git a/scripts/portmaster/NETfishing.sh b/scripts/portmaster/NETfishing.sh
index 43cd7e4..fe23caf 100755
--- a/scripts/portmaster/NETfishing.sh
+++ b/scripts/portmaster/NETfishing.sh
@@ -29,6 +29,7 @@ fi
 
 CONFDIR="$GAMEDIR/conf"
 GAME_EXECUTABLE="$GAMEDIR/NETfishing.aarch64"
+GPTOKEYB_CONFIG="$GAMEDIR/netfishing.gptk"
 WESTON_DIR="/tmp/netfishing-weston"
 WESTON_RUNTIME="weston_pkg_0.2"
 HARBOURMASTER="$controlfolder/harbourmaster"
@@ -118,9 +119,10 @@ case "$PERFORMANCE_PROFILE" in
 esac
 
 # Keep NETfishing's native controller input separate from PortMaster's exit
-# handling. Without a -c mapping file, GPTOKEYB only watches for the
-# device-specific force-quit chord and does not inject gameplay inputs.
-$GPTOKEYB "NETfishing.aarch64" &
+# handling. Legacy GPTOKEYB builds can load their default keyboard map when no
+# config is supplied, so the explicit no-op map preserves only the
+# device-specific force-quit chord.
+$GPTOKEYB "NETfishing.aarch64" -c "$GPTOKEYB_CONFIG" &
 pm_platform_helper "$GAME_EXECUTABLE"
 
 $ESUDO env \
diff --git a/scripts/portmaster/netfishing.gptk b/scripts/portmaster/netfishing.gptk
new file mode 100644
index 0000000..ac03270
--- /dev/null
+++ b/scripts/portmaster/netfishing.gptk
@@ -0,0 +1,40 @@
+# NETfishing reads the controller directly. GPTOKEYB is retained only for the
+# PortMaster force-quit chord, so every keyboard and mouse binding is disabled.
+
+back = \"
+guide = \"
+start = \"
+
+a = \"
+a_hk = \"
+b = \"
+b_hk = \"
+x = \"
+x_hk = \"
+y = \"
+y_hk = \"
+
+l1 = \"
+l1_hk = \"
+l2 = \"
+l2_hk = \"
+l3 = \"
+r1 = \"
+r1_hk = \"
+r2 = \"
+r2_hk = \"
+r3 = \"
+
+up = \"
+down = \"
+left = \"
+right = \"
+
+left_analog_up = \"
+left_analog_down = \"
+left_analog_left = \"
+left_analog_right = \"
+right_analog_up = \"
+right_analog_down = \"
+right_analog_left = \"
+right_analog_right = \"