diff --git a/core/libs/prx/libSceSysmodule/Export.cpp b/core/libs/prx/libSceSysmodule/Export.cpp
index 0dd8ea293..8ed923947 100644
--- a/core/libs/prx/libSceSysmodule/Export.cpp
+++ b/core/libs/prx/libSceSysmodule/Export.cpp
@@ -20,6 +20,7 @@ extern "C" void* APS5_VABI dlopen_nid_postfix(const char* path, int flags);
 
 namespace {
 
+constexpr int SCE_SYSMODULE_ERROR_INVALID_VALUE = static_cast<int>(0x805A1000);
 constexpr int SCE_SYSMODULE_ERROR_UNLOADED = static_cast<int>(0x805A1001);
 constexpr int kRtldNow = 2;
 
@@ -117,7 +118,7 @@ int APS5_VABI sceSysmoduleGetModuleHandleInternal(std::uint32_t id, std::int32_t
 
 int APS5_VABI sceSysmoduleIsLoaded(std::uint16_t id) {
     if (id == 0) {
-        throw std::runtime_error("sceSysmoduleIsLoaded: invalid id 0");
+        return SCE_SYSMODULE_ERROR_INVALID_VALUE;
     }
     if (!findModuleName(id)) {
         APS5_LOG_OUT("unknown id: %u", static_cast<unsigned>(id));
@@ -134,7 +135,7 @@ int APS5_VABI sceSysmoduleIsLoaded(std::uint16_t id) {
 
 int APS5_VABI sceSysmoduleLoadModule(std::uint16_t id) {
     if (id == 0) {
-        throw std::runtime_error("sceSysmoduleLoadModule: invalid id 0");
+        return SCE_SYSMODULE_ERROR_INVALID_VALUE;
     }
     if (!findModuleName(id)) {
         APS5_LOG_OUT("unknown id: %u", static_cast<unsigned>(id));
@@ -151,7 +152,7 @@ int APS5_VABI sceSysmoduleLoadModuleInternalWithArg(std::uint32_t id, int argc,
     (void)argv;
     (void)unk;
     if ((id & 0x7fffffffu) == 0) {
-        throw std::runtime_error("sceSysmoduleLoadModuleInternalWithArg: invalid id 0");
+        return SCE_SYSMODULE_ERROR_INVALID_VALUE;
     }
     if (!findModuleName(id)) {
         throw std::runtime_error(std::string("sceSysmoduleLoadModuleInternalWithArg: unknown id ") + std::to_string(id));
@@ -166,7 +167,7 @@ int APS5_VABI sceSysmoduleLoadModuleInternalWithArg(std::uint32_t id, int argc,
 
 int APS5_VABI sceSysmoduleUnloadModule(std::uint16_t id) {
     if (id == 0) {
-        throw std::runtime_error("sceSysmoduleUnloadModule: invalid id 0");
+        return SCE_SYSMODULE_ERROR_INVALID_VALUE;
     }
     if (!findModuleName(id)) {
         APS5_LOG_OUT("unknown id: %u", static_cast<unsigned>(id));
@@ -183,7 +184,7 @@ int APS5_VABI sceSysmoduleUnloadModule(std::uint16_t id) {
 
 int APS5_VABI sceSysmoduleLoadModuleInternal(std::uint32_t id) {
     if ((id & 0x7fffffffu) == 0) {
-        throw std::runtime_error("sceSysmoduleLoadModuleInternal: invalid id 0");
+        return SCE_SYSMODULE_ERROR_INVALID_VALUE;
     }
     if (!findModuleName(id)) {
         throw std::runtime_error(std::string("sceSysmoduleLoadModuleInternal: unknown id ") + std::to_string(id));
@@ -195,7 +196,7 @@ int APS5_VABI sceSysmoduleLoadModuleInternal(std::uint32_t id) {
 
 int APS5_VABI sceSysmoduleUnloadModuleInternal(std::uint32_t id) {
     if ((id & 0x7fffffffu) == 0) {
-        throw std::runtime_error("sceSysmoduleUnloadModuleInternal: invalid id 0");
+        return SCE_SYSMODULE_ERROR_INVALID_VALUE;
     }
     if (!findModuleName(id)) {
         throw std::runtime_error(std::string("sceSysmoduleUnloadModuleInternal: unknown id ") + std::to_string(id));
diff --git a/core/libs/tests/GuestSysmodule.cpp b/core/libs/tests/GuestSysmodule.cpp
index 4a63bbd37..8c24e9a17 100644
--- a/core/libs/tests/GuestSysmodule.cpp
+++ b/core/libs/tests/GuestSysmodule.cpp
@@ -2,6 +2,7 @@
 #include "prx/libc/include/general/VabiMacros.hpp"
 #include <cstdint>
 #include <cstdlib>
+#include <initializer_list>
 #include <stdexcept>
 #include <string>
 #ifdef __linux__
@@ -17,6 +18,7 @@ int APS5_VABI sceSysmoduleLoadModule(std::uint16_t id);
 int APS5_VABI sceSysmoduleUnloadModule(std::uint16_t id);
 int APS5_VABI sceSysmoduleLoadModuleInternal(std::uint32_t id);
 int APS5_VABI sceSysmoduleUnloadModuleInternal(std::uint32_t id);
+int APS5_VABI sceSysmoduleLoadModuleInternalWithArg(std::uint32_t id, int argc, void* argv, std::uint64_t unk, int* ret);
 int APS5_VABI sceSysmoduleGetModuleInfoForUnwind(std::uint64_t addr, int flags, ModuleInfoForUnwind* info);
 int APS5_VABI sceSysmoduleGetModuleHandleInternal(std::uint32_t id, std::int32_t* handle);
 int APS5_VABI sceKernelDlsym(std::int32_t handle, const char* symbol, void** addr);
@@ -38,7 +40,9 @@ bool ThrowsRuntimeError(TFunction function) {
 
 constexpr std::uint16_t kFiberModuleId = 0x0006;
 constexpr std::uint16_t kUltModuleId = 0x0007;
+constexpr int kInvalidValue = static_cast<int>(0x805A1000);
 constexpr int kModuleUnloaded = static_cast<int>(0x805A1001);
+constexpr std::uint32_t kInternalFlag = 0x80000000u;
 constexpr std::uint16_t kTrophy2ModuleId = 0x0110;
 
 #ifdef __linux__
@@ -98,6 +102,17 @@ void CheckUnwindInfo() {
 }
 
 int main() {
+    Require(sceSysmoduleIsLoaded(0) == kInvalidValue);
+    Require(sceSysmoduleLoadModule(0) == kInvalidValue);
+    Require(sceSysmoduleUnloadModule(0) == kInvalidValue);
+    for (std::uint32_t id : {0u, kInternalFlag}) {
+        Require(sceSysmoduleLoadModuleInternal(id) == kInvalidValue);
+        Require(sceSysmoduleUnloadModuleInternal(id) == kInvalidValue);
+        int result = 0x5a5a5a5a;
+        Require(sceSysmoduleLoadModuleInternalWithArg(id, 0, nullptr, 0, &result) == kInvalidValue);
+        Require(result == 0x5a5a5a5a);
+    }
+
     Require(sceSysmoduleIsLoaded(kFiberModuleId) == kModuleUnloaded);
     Require(sceSysmoduleLoadModuleInternal(kFiberModuleId) == 0);
     Require(sceSysmoduleIsLoaded(kFiberModuleId) == 0);