diff --git a/core/libs/prx/libSceAudioOut/src/AudioOut2Mastering.cpp b/core/libs/prx/libSceAudioOut/src/AudioOut2Mastering.cpp
index ac3f33976..4cbf76ef1 100644
--- a/core/libs/prx/libSceAudioOut/src/AudioOut2Mastering.cpp
+++ b/core/libs/prx/libSceAudioOut/src/AudioOut2Mastering.cpp
@@ -23,10 +23,9 @@ int APS5_VABI sceAudioOut2MasteringGetState(AudioOut2MasteringStatesHeader* stat
 }
 
 int APS5_VABI sceAudioOut2MasteringSetParam(const AudioOut2MasteringParamsHeader* param, uint32_t output, uint32_t flags) {
-    (void)param;
     (void)output;
     (void)flags;
-    NotImplemented_nid_no_patch(__func__);
+    if (param == nullptr) NotImplemented_nid_no_patch(__func__);
     return 0;
 }
 
diff --git a/core/libs/prx/libSceAudioOut/tests/AudioOut2Latency.cpp b/core/libs/prx/libSceAudioOut/tests/AudioOut2Latency.cpp
index c0882d45c..5c655c401 100644
--- a/core/libs/prx/libSceAudioOut/tests/AudioOut2Latency.cpp
+++ b/core/libs/prx/libSceAudioOut/tests/AudioOut2Latency.cpp
@@ -9,6 +9,7 @@ extern "C" {
 int APS5_VABI sceAudioOut2Initialize();
 int APS5_VABI sceAudioOut2Set3DLatency(int, std::uint32_t);
 int APS5_VABI sceAudioOut2MasteringInit(std::uint32_t);
+int APS5_VABI sceAudioOut2MasteringSetParam(const void*, std::uint32_t, std::uint32_t);
 }
 
 static void Require(bool value, const char* message) {
@@ -46,11 +47,18 @@ void TestMasteringInit() {
     Require(ThrowsRuntimeError([] { sceAudioOut2MasteringInit(1); }), "flags 1 must throw");
 }
 
+void TestMasteringSetParam() {
+    const std::uint32_t params[4] = {1u, 0u, 0u, 0u};
+    Require(sceAudioOut2MasteringSetParam(params, 0, 0) == 0, "mastering parameters must be accepted");
+    Require(ThrowsRuntimeError([] { sceAudioOut2MasteringSetParam(nullptr, 0, 0); }), "null mastering parameters must throw");
+}
+
 }
 
 int main() {
     Require(sceAudioOut2Initialize() == 0, "initialization must succeed");
     TestSet3DLatency();
     TestMasteringInit();
+    TestMasteringSetParam();
     return 0;
 }
diff --git a/docs/dev/TechnicalDebt.md b/docs/dev/TechnicalDebt.md
index 61a82baf3..e1db2ff13 100644
--- a/docs/dev/TechnicalDebt.md
+++ b/docs/dev/TechnicalDebt.md
@@ -247,7 +247,7 @@ Throughout the project, every function at every stage either **does exactly what
 - `--to-intel` guest module trampolines are covered only by a synthetic relinker test; no game title has been verified with them on Linux or Windows.
 - `--to-intel` replaces the approximate VEX.128 register forms of VRSQRTPS and VRCPPS with [correctly rounded](../../core/relinker/codegen/src/x86/ReciprocalLowering.cpp) 1/sqrt(x) and 1/x, not with the AMD approximation: its tables are not public. Intel's approximation of 1/sqrt(1.0) is 0x3F7FF000, and two Newton-Raphson steps on it settle on 0.99999994 instead of 1.0; a renormalised identity quaternion then turns into a NaN axis in PPSA21564, which the console does not show. Refined results now reach the exact value; unrefined ones can still differ from the console in the low bits. Each site costs an out-of-line stub (two jumps, a spill below the red zone, SQRTPS/DIVPS). The 256-bit, scalar, legacy and memory forms keep the native instruction, as does a 4-byte site with no movable instruction after it for the jump (5 sites in PPSA21564).
 - [sceKeyboardGetKey2Char](../../core/libs/prx/libSceKeyboard/src/keyboard_impl.cpp) (libSceKeyboard) translates the 101-key (US) arrangement and the alphanumeric layer of the 106-key (Japanese) one, which follows the JIS layout of the HID usages: the Yen (0x89) and Ro (0x87) keys return `\` (0x5C) unshifted, as JIS X 0201 places the yen sign there; whether the console returns U+00A5 instead is unverified. With the Kana LED (bit 4, the HID position) set the 106-key arrangement throws, as the kana the console returns are unknown. Ctrl and Alt do not change the character.
-- [sceAudioOut2Set3DLatency](../../core/libs/prx/libSceAudioOut/src/AudioOut2System.cpp) and [sceAudioOut2MasteringInit](../../core/libs/prx/libSceAudioOut/src/AudioOut2Mastering.cpp) (libSceAudioOut) have no effect: there is no 3D rendering or mastering stage.
+- [sceAudioOut2Set3DLatency](../../core/libs/prx/libSceAudioOut/src/AudioOut2System.cpp) and [sceAudioOut2MasteringInit and sceAudioOut2MasteringSetParam](../../core/libs/prx/libSceAudioOut/src/AudioOut2Mastering.cpp) (libSceAudioOut) have no effect: there is no 3D rendering or mastering stage.
 - [sceImeKeyboardGetInfo](../../core/libs/prx/libSceIme/Export.cpp) (libSceIme) returns `0x80bc0023` (no resource id) for every id while a keyboard is open, since the IME keyboard never reports a connected device. [sceImeKeyboardSetMode](../../core/libs/prx/libSceIme/Export.cpp) validates the mode bits but the mode has no effect, as no IME keyboard events are delivered.
 - [libSceAudiodec](../../core/libs/prx/libSceAudiodec/Export.cpp) throws for the 24-bit PCM word size (`iBwPcm` 0): its sample layout is unknown. ATRAC9 decoding is covered only by configuration and error tests, as no ATRAC9 encoder is available for a fixture.
 - [sceAjmDecMp3ParseFrame](../../core/libs/prx/libSceAjm.native/src/Ajm.cpp) (libSceAjm.native) throws when the original file length is requested (`parse_ofl` non-zero) for a layer other than III, for a CRC-protected frame, or for a VBRI header outside MPEG-1 stereo: shadPS4 looks for the tag after the CRC and after the side information, while LAME and FFmpeg place it without the CRC and VBRI always at byte 36.