diff --git a/Kernel/Process.h b/Kernel/Process.h
index d262cf2a5f..317c1fa16d 100644
--- a/Kernel/Process.h
+++ b/Kernel/Process.h
@@ -223,7 +223,7 @@ public:
     [[noreturn]] void sys$exit(int status);
     int sys$sigreturn(RegisterState& registers);
     pid_t sys$waitid(Userspace<const Syscall::SC_waitid_params*>);
-    void* sys$mmap(const Syscall::SC_mmap_params*);
+    void* sys$mmap(Userspace<const Syscall::SC_mmap_params*>);
     int sys$munmap(void*, size_t size);
     int sys$set_mmap_name(const Syscall::SC_set_mmap_name_params*);
     int sys$mprotect(void*, size_t, int prot);
diff --git a/Kernel/Syscalls/mmap.cpp b/Kernel/Syscalls/mmap.cpp
index 416a9694b6..243d035008 100644
--- a/Kernel/Syscalls/mmap.cpp
+++ b/Kernel/Syscalls/mmap.cpp
@@ -76,7 +76,7 @@ static bool validate_inode_mmap_prot(const Process& process, int prot, const Ino
     return true;
 }
 
-void* Process::sys$mmap(const Syscall::SC_mmap_params* user_params)
+void* Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
 {
     REQUIRE_PROMISE(stdio);