diff --git a/src/core/libraries/kernel/thread_management.cpp b/src/core/libraries/kernel/thread_management.cpp
index 567fff18..567ac867 100644
--- a/src/core/libraries/kernel/thread_management.cpp
+++ b/src/core/libraries/kernel/thread_management.cpp
@@ -510,23 +510,24 @@ int PS4_SYSV_ABI scePthreadMutexattrInit(ScePthreadMutexattr* attr) {
 int PS4_SYSV_ABI scePthreadMutexattrSettype(ScePthreadMutexattr* attr, int type) {
     int ptype = PTHREAD_MUTEX_DEFAULT;
     switch (type) {
-    case 1:
+    case ORBIS_PTHREAD_MUTEX_ERRORCHECK:
         ptype = PTHREAD_MUTEX_ERRORCHECK;
         break;
-    case 2:
+    case ORBIS_PTHREAD_MUTEX_RECURSIVE:
         ptype = PTHREAD_MUTEX_RECURSIVE;
         break;
-    case 3:
-    case 4:
+    case ORBIS_PTHREAD_MUTEX_NORMAL:
+    case ORBIS_PTHREAD_MUTEX_ADAPTIVE:
         ptype = PTHREAD_MUTEX_NORMAL;
         break;
     default:
-        UNREACHABLE_MSG("Invalid type: {}", type);
+        return SCE_KERNEL_ERROR_EINVAL;
     }
 
     int result = pthread_mutexattr_settype(&(*attr)->pth_mutex_attr, ptype);
+    ASSERT(result == 0);
 
-    return result == 0 ? SCE_OK : SCE_KERNEL_ERROR_EINVAL;
+    return SCE_OK;
 }
 
 int PS4_SYSV_ABI scePthreadMutexattrSetprotocol(ScePthreadMutexattr* attr, int protocol) {
diff --git a/src/core/libraries/kernel/thread_management.h b/src/core/libraries/kernel/thread_management.h
index c5935275..3679af84 100644
--- a/src/core/libraries/kernel/thread_management.h
+++ b/src/core/libraries/kernel/thread_management.h
@@ -20,6 +20,11 @@ constexpr int ORBIS_KERNEL_PRIO_FIFO_DEFAULT = 700;
 constexpr int ORBIS_KERNEL_PRIO_FIFO_HIGHEST = 256;
 constexpr int ORBIS_KERNEL_PRIO_FIFO_LOWEST = 767;
 
+constexpr int ORBIS_PTHREAD_MUTEX_ERRORCHECK = 1;
+constexpr int ORBIS_PTHREAD_MUTEX_RECURSIVE = 2;
+constexpr int ORBIS_PTHREAD_MUTEX_NORMAL = 3;
+constexpr int ORBIS_PTHREAD_MUTEX_ADAPTIVE = 4;
+
 struct PthreadInternal;
 struct PthreadAttrInternal;
 struct PthreadMutexInternal;