diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index 314d2df948..7b409876f3 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -2861,16 +2861,23 @@ int Process::thread_count() const
     return count;
 }
 
-int Process::sys$create_thread(void* (*entry)(void*), void* argument)
+int Process::sys$create_thread(void* (*entry)(void*), void* argument, void* stack)
 {
     if (!validate_read((const void*)entry, sizeof(void*)))
         return -EFAULT;
+    if (!MM.validate_user_stack(*this, VirtualAddress(((u32)stack) - 4)))
+        return -EFAULT;
     auto* thread = new Thread(*this);
     auto& tss = thread->tss();
     tss.eip = (u32)entry;
     tss.eflags = 0x0202;
     tss.cr3 = page_directory().cr3();
-    thread->make_userspace_stack_for_secondary_thread(argument);
+    tss.esp = (u32)stack;
+
+    // NOTE: The stack needs to be 16-byte aligned.
+    thread->push_value_on_stack((u32)argument);
+    thread->push_value_on_stack(0);
+
     thread->make_thread_specific_region({});
     thread->set_state(Thread::State::Runnable);
     return thread->tid();
diff --git a/Kernel/Process.h b/Kernel/Process.h
index 1e912aaa61..58a2d39887 100644
--- a/Kernel/Process.h
+++ b/Kernel/Process.h
@@ -204,7 +204,7 @@ public:
     int sys$sched_setparam(pid_t pid, const struct sched_param* param);
     int sys$sched_getparam(pid_t pid, struct sched_param* param);
     int sys$restore_signal_mask(u32 mask);
-    int sys$create_thread(void* (*)(void*), void*);
+    int sys$create_thread(void* (*)(void*), void* argument, void* stack);
     void sys$exit_thread(void*);
     int sys$join_thread(int tid, void** exit_value);
     int sys$rename(const char* oldpath, const char* newpath);
diff --git a/Kernel/Thread.cpp b/Kernel/Thread.cpp
index f1034e61e4..84bf19188a 100644
--- a/Kernel/Thread.cpp
+++ b/Kernel/Thread.cpp
@@ -601,18 +601,6 @@ void Thread::make_userspace_stack_for_main_thread(Vector<String> arguments, Vect
     push_value_on_stack(0);
 }
 
-void Thread::make_userspace_stack_for_secondary_thread(void* argument)
-{
-    m_userspace_stack_region = m_process.allocate_region(VirtualAddress(), default_userspace_stack_size, String::format("Stack (Thread %d)", tid()), PROT_READ | PROT_WRITE, false);
-    ASSERT(m_userspace_stack_region);
-    m_userspace_stack_region->set_stack(true);
-    m_tss.esp = m_userspace_stack_region->vaddr().offset(default_userspace_stack_size).get();
-
-    // NOTE: The stack needs to be 16-byte aligned.
-    push_value_on_stack((u32)argument);
-    push_value_on_stack(0);
-}
-
 Thread* Thread::clone(Process& process)
 {
     auto* clone = new Thread(process);
diff --git a/Kernel/Thread.h b/Kernel/Thread.h
index 0fd9b9ad37..7017df3dd9 100644
--- a/Kernel/Thread.h
+++ b/Kernel/Thread.h
@@ -325,7 +325,6 @@ public:
     void set_default_signal_dispositions();
     void push_value_on_stack(u32);
     void make_userspace_stack_for_main_thread(Vector<String> arguments, Vector<String> environment);
-    void make_userspace_stack_for_secondary_thread(void* argument);
 
     void make_thread_specific_region(Badge<Process>);
 
diff --git a/Libraries/LibC/unistd.cpp b/Libraries/LibC/unistd.cpp
index d0f6af955a..809d705187 100644
--- a/Libraries/LibC/unistd.cpp
+++ b/Libraries/LibC/unistd.cpp
@@ -509,18 +509,6 @@ char* getlogin()
     return nullptr;
 }
 
-int create_thread(void* (*entry)(void*), void* argument)
-{
-    int rc = syscall(SC_create_thread, entry, argument);
-    __RETURN_WITH_ERRNO(rc, rc, -1);
-}
-
-void exit_thread(void* code)
-{
-    syscall(SC_exit_thread, code);
-    ASSERT_NOT_REACHED();
-}
-
 int ftruncate(int fd, off_t length)
 {
     int rc = syscall(SC_ftruncate, fd, length);
diff --git a/Libraries/LibC/unistd.h b/Libraries/LibC/unistd.h
index 8f57122693..c7999b335c 100644
--- a/Libraries/LibC/unistd.h
+++ b/Libraries/LibC/unistd.h
@@ -35,8 +35,6 @@ void sysbeep();
 int systrace(pid_t);
 int gettid();
 int donate(int tid);
-int create_thread(void *(*)(void*), void* argument);
-void exit_thread(void*);
 int create_shared_buffer(int, void** buffer);
 int share_buffer_with(int, pid_t peer_pid);
 int share_buffer_globally(int);
diff --git a/Libraries/LibPthread/pthread.cpp b/Libraries/LibPthread/pthread.cpp
index b1e17b1f61..ba844ce400 100644
--- a/Libraries/LibPthread/pthread.cpp
+++ b/Libraries/LibPthread/pthread.cpp
@@ -1,18 +1,36 @@
+#include <AK/Assertions.h>
 #include <AK/Atomic.h>
 #include <AK/StdLibExtras.h>
 #include <Kernel/Syscall.h>
 #include <pthread.h>
-#include <unistd.h>
 #include <stdio.h>
+#include <sys/mman.h>
+#include <unistd.h>
 
 extern "C" {
 
+static int create_thread(void* (*entry)(void*), void* argument, void* stack)
+{
+    int rc = syscall(SC_create_thread, entry, argument, stack);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+
+static void exit_thread(void* code)
+{
+    syscall(SC_exit_thread, code);
+    ASSERT_NOT_REACHED();
+}
+
 int pthread_create(pthread_t* thread, pthread_attr_t* attributes, void* (*start_routine)(void*), void* argument_to_start_routine)
 {
     if (!thread)
         return -EINVAL;
     UNUSED_PARAM(attributes);
-    int rc = create_thread(start_routine, argument_to_start_routine);
+    const size_t stack_size = 4 * MB;
+    auto* stack = (u8*)mmap_with_name(nullptr, stack_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, 0, 0, "Thread stack");
+    if (!stack)
+        return -1;
+    int rc = create_thread(start_routine, argument_to_start_routine, stack + stack_size);
     if (rc < 0)
         return rc;
     *thread = rc;
@@ -55,5 +73,4 @@ int pthread_mutex_unlock(pthread_mutex_t* mutex)
     atomic->store(false, AK::memory_order_release);
     return 0;
 }
-
 }