diff --git a/kernel/fs/vfs.c b/kernel/fs/vfs.c
index f1f4949..ac69bee 100644
--- a/kernel/fs/vfs.c
+++ b/kernel/fs/vfs.c
@@ -100,6 +100,12 @@ int vfs_open (struct procgroup* procgroup, const char* mountpoint, const char* p
 
   int id = handle->id = id_alloc (&procgroup->vfs_handle_id_alloc);
 
+  if (id < 0) {
+    free (handle);
+    spin_unlock (&procgroup->lock);
+    return -ST_OOM_ERROR;
+  }
+
   rbtree_insert (struct vfs_handle, &procgroup->vfs_handle_tree, &handle->handle_tree_link,
                  handle_tree_link, id);
 
diff --git a/kernel/proc/procgroup.c b/kernel/proc/procgroup.c
index 657198f..743f557 100644
--- a/kernel/proc/procgroup.c
+++ b/kernel/proc/procgroup.c
@@ -156,9 +156,17 @@ struct procgroup* procgroup_create (void) {
     return NULL;
   }
 
+  if (!id_alloc_init (&procgroup->rid_alloc, PROCGROUP_RESOURCES_MAX)) {
+    id_alloc_fini (&procgroup->vfs_handle_id_alloc);
+    free (procgroup);
+    return NULL;
+  }
+
   procgroup->pgid = id_alloc (&pgid_alloc);
 
   if (procgroup->pgid < 0) {
+    id_alloc_fini (&procgroup->rid_alloc);
+    id_alloc_fini (&procgroup->vfs_handle_id_alloc);
     free (procgroup);
     return NULL;
   }
@@ -168,7 +176,9 @@ struct procgroup* procgroup_create (void) {
   procgroup->pd.cr3_paddr = mm_alloc_user_pd_phys ();
   procgroup->map_base = PROC_MAP_BASE;
 
-  if (proc_create_resource_mail (procgroup, 1) == NULL) {
+  if (proc_create_resource_mail (procgroup) == NULL) {
+    id_alloc_fini (&procgroup->rid_alloc);
+    id_alloc_fini (&procgroup->vfs_handle_id_alloc);
     free (procgroup);
     return NULL;
   }
@@ -224,7 +234,7 @@ static void procgroup_delete (struct procgroup* procgroup, struct reschedule_ctx
 
     list_remove (resource_delete_list, &resource->delete_list_link);
 
-    proc_delete_resource (resource, rctx);
+    proc_delete_resource (procgroup, resource, rctx);
   }
 
   /* unlock VFS owned mountpoints */
@@ -245,6 +255,7 @@ static void procgroup_delete (struct procgroup* procgroup, struct reschedule_ctx
   free (procgroup->tls.tls_tmpl);
 
   id_alloc_fini (&procgroup->vfs_handle_id_alloc);
+  id_alloc_fini (&procgroup->rid_alloc);
   id_free (&pgid_alloc, procgroup->pgid);
 
   free (procgroup);
diff --git a/kernel/proc/procgroup.h b/kernel/proc/procgroup.h
index 323b37d..c06d67f 100644
--- a/kernel/proc/procgroup.h
+++ b/kernel/proc/procgroup.h
@@ -11,6 +11,7 @@
 #include <sys/procgroup.h>
 
 #define PROCGROUP_VFS_HANDLES_MAX 256
+#define PROCGROUP_RESOURCES_MAX   256
 
 struct proc;
 struct reschedule_ctx;
@@ -29,6 +30,7 @@ struct procgroup {
   struct rb_node_link* memb_proc_tree;
   spin_lock_t lock;
   struct rb_node_link* resource_tree;
+  struct id_alloc rid_alloc;
   struct pd pd;
   struct list_node_link* mappings;
   uintptr_t map_base;
diff --git a/kernel/proc/resource.c b/kernel/proc/resource.c
index 0cc8b06..0855158 100644
--- a/kernel/proc/resource.c
+++ b/kernel/proc/resource.c
@@ -1,3 +1,4 @@
+#include <id/id_alloc.h>
 #include <libk/assert.h>
 #include <libk/list.h>
 #include <libk/rbtree.h>
@@ -25,64 +26,87 @@ struct proc_resource* proc_find_resource (struct procgroup* procgroup, int rid)
   return resource;
 }
 
-struct proc_resource* proc_create_resource_mutex (struct procgroup* procgroup, int rid) {
+struct proc_resource* proc_create_resource_mutex (struct procgroup* procgroup) {
   struct proc_resource* resource;
 
-  resource = proc_find_resource (procgroup, rid);
-  if (resource != NULL)
-    return resource;
-
   resource = malloc (sizeof (*resource));
   if (resource == NULL)
     return NULL;
 
   memset (resource, 0, sizeof (*resource));
-  resource->lock = SPIN_LOCK_INIT;
-  resource->ops.cleanup = &proc_cleanup_resource_mutex;
-  resource->u.mutex.resource = resource;
-  resource->rid = rid;
-  resource->type = PR_MUTEX;
 
   spin_lock (&procgroup->lock);
-  rbtree_insert (struct proc_resource, &procgroup->resource_tree, &resource->resource_tree_link,
-                 resource_tree_link, rid);
-  spin_unlock (&procgroup->lock);
 
-  return resource;
-}
+  resource->rid = id_alloc (&procgroup->rid_alloc);
 
-struct proc_resource* proc_create_resource_mail (struct procgroup* procgroup, int rid) {
-  struct proc_resource* resource;
-
-  resource = proc_find_resource (procgroup, rid);
-  if (resource != NULL)
-    return resource;
-
-  resource = malloc (sizeof (*resource));
-  if (resource == NULL)
-    return NULL;
-
-  memset (resource, 0, sizeof (*resource));
-  resource->lock = SPIN_LOCK_INIT;
-  resource->ops.cleanup = &proc_cleanup_resource_mail;
-  resource->u.mail.resource = resource;
-  resource->rid = rid;
-  resource->type = PR_MAIL;
-
-  if (!ringbuffer_init (&resource->u.mail.ringbuffer, PROC_MAIL_MAX, sizeof (struct mail_packet))) {
+  if (resource->rid < 0) {
     free (resource);
+    spin_unlock (&procgroup->lock);
     return NULL;
   }
 
-  spin_lock (&procgroup->lock);
+  resource->lock = SPIN_LOCK_INIT;
+  resource->ops.cleanup = &proc_cleanup_resource_mutex;
+  resource->u.mutex.resource = resource;
+  resource->type = PR_MUTEX;
+
   rbtree_insert (struct proc_resource, &procgroup->resource_tree, &resource->resource_tree_link,
                  resource_tree_link, rid);
+
   spin_unlock (&procgroup->lock);
 
   return resource;
 }
 
-void proc_delete_resource (struct proc_resource* resource, struct reschedule_ctx* rctx) {
+struct proc_resource* proc_create_resource_mail (struct procgroup* procgroup) {
+  struct proc_resource* resource;
+
+  resource = malloc (sizeof (*resource));
+  if (resource == NULL)
+    return NULL;
+
+  memset (resource, 0, sizeof (*resource));
+
+  spin_lock (&procgroup->lock);
+
+  resource->rid = id_alloc (&procgroup->rid_alloc);
+
+  if (resource->rid < 0) {
+    free (resource);
+    spin_unlock (&procgroup->lock);
+    return NULL;
+  }
+
+  resource->lock = SPIN_LOCK_INIT;
+  resource->ops.cleanup = &proc_cleanup_resource_mail;
+  resource->u.mail.resource = resource;
+  resource->type = PR_MAIL;
+
+  if (!ringbuffer_init (&resource->u.mail.ringbuffer, PROC_MAIL_MAX, sizeof (struct mail_packet))) {
+    id_free (&procgroup->rid_alloc, resource->rid);
+    free (resource);
+    spin_unlock (&procgroup->lock);
+    return NULL;
+  }
+
+  rbtree_insert (struct proc_resource, &procgroup->resource_tree, &resource->resource_tree_link,
+                 resource_tree_link, rid);
+
+  spin_unlock (&procgroup->lock);
+
+  return resource;
+}
+
+void proc_delete_resource (struct procgroup* procgroup, struct proc_resource* resource,
+                           struct reschedule_ctx* rctx) {
+  spin_lock (&procgroup->lock);
+  spin_lock (&resource->lock);
+
+  id_free (&procgroup->rid_alloc, resource->rid);
+
+  spin_unlock (&resource->lock);
+  spin_unlock (&procgroup->lock);
+
   resource->ops.cleanup (resource, rctx);
   free (resource);
 }
diff --git a/kernel/proc/resource.h b/kernel/proc/resource.h
index 94fdeb7..9bc038d 100644
--- a/kernel/proc/resource.h
+++ b/kernel/proc/resource.h
@@ -33,10 +33,11 @@ struct proc_resource {
 
 struct proc_resource* proc_find_resource (struct procgroup* procgroup, int rid);
 
-struct proc_resource* proc_create_resource_mutex (struct procgroup* procgroup, int rid);
+struct proc_resource* proc_create_resource_mutex (struct procgroup* procgroup);
 
-struct proc_resource* proc_create_resource_mail (struct procgroup* procgroup, int rid);
+struct proc_resource* proc_create_resource_mail (struct procgroup* procgroup);
 
-void proc_delete_resource (struct proc_resource* resource, struct reschedule_ctx* rctx);
+void proc_delete_resource (struct procgroup* procgroup, struct proc_resource* resource,
+                           struct reschedule_ctx* rctx);
 
 #endif // _KERNEL_PROC_RESOURCE_H
diff --git a/kernel/syscall/syscall.c b/kernel/syscall/syscall.c
index 40b46ae..5722e51 100644
--- a/kernel/syscall/syscall.c
+++ b/kernel/syscall/syscall.c
@@ -113,11 +113,9 @@ DEFINE_SYSCALL (sys_sched) {
   return SYSRESULT (ST_OK);
 }
 
-/* int mutex_create (int mutex_rid) */
+/* int mutex_create (void) */
 DEFINE_SYSCALL (sys_mutex_create) {
-  int mutex_rid = (int)a1;
-
-  struct proc_resource* mutex_resource = proc_create_resource_mutex (proc->procgroup, mutex_rid);
+  struct proc_resource* mutex_resource = proc_create_resource_mutex (proc->procgroup);
 
   if (mutex_resource == NULL)
     return SYSRESULT (-ST_OOM_ERROR);
@@ -134,7 +132,7 @@ DEFINE_SYSCALL (sys_mutex_delete) {
   if (mutex_resource == NULL)
     return SYSRESULT (-ST_NOT_FOUND);
 
-  proc_delete_resource (mutex_resource, rctx);
+  proc_delete_resource (proc->procgroup, mutex_resource, rctx);
 
   return SYSRESULT (ST_OK);
 }
@@ -183,7 +181,7 @@ DEFINE_SYSCALL (sys_mail_send) {
   if (procgroup == NULL)
     return SYSRESULT (-ST_NOT_FOUND);
 
-  struct proc_resource* mail_resource = proc_find_resource (procgroup, 1);
+  struct proc_resource* mail_resource = proc_find_resource (procgroup, 0);
 
   if (mail_resource == NULL)
     return SYSRESULT (-ST_NOT_FOUND);
@@ -203,7 +201,7 @@ DEFINE_SYSCALL (sys_mail_receive) {
   if (mesg == NULL)
     return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
 
-  struct proc_resource* mail_resource = proc_find_resource (proc->procgroup, 1);
+  struct proc_resource* mail_resource = proc_find_resource (proc->procgroup, 0);
 
   if (mail_resource == NULL)
     return SYSRESULT (-ST_NOT_FOUND);
diff --git a/liballoc/liballoc.c b/liballoc/liballoc.c
index cbbe8d6..c9b477b 100644
--- a/liballoc/liballoc.c
+++ b/liballoc/liballoc.c
@@ -4,15 +4,15 @@
 #include <liballoc.h>
 #include <system.h>
 
-#define LIBALLOC_MUTEX 500
+int liballoc_mutex;
 
-void liballoc_init (void) { mutex_create (LIBALLOC_MUTEX); }
+void liballoc_init (void) { liballoc_mutex = mutex_create (); }
 
-void liballoc_deinit (void) { mutex_delete (LIBALLOC_MUTEX); }
+void liballoc_deinit (void) { mutex_delete (liballoc_mutex); }
 
-int liballoc_lock (void) { return mutex_lock (LIBALLOC_MUTEX); }
+int liballoc_lock (void) { return mutex_lock (liballoc_mutex); }
 
-int liballoc_unlock (void) { return mutex_unlock (LIBALLOC_MUTEX); }
+int liballoc_unlock (void) { return mutex_unlock (liballoc_mutex); }
 
 void* liballoc_alloc (int pages) { return map (0, pages, MAP_FLAGS | MAP_RW); }
 
diff --git a/libsystem/system.c b/libsystem/system.c
index 2fd48f4..01c2cdb 100644
--- a/libsystem/system.c
+++ b/libsystem/system.c
@@ -25,7 +25,7 @@ int clone (uintptr_t vstack_top, void (*entry) (void), void* argument_ptr) {
   return do_syscall (SYS_CLONE, vstack_top, entry, argument_ptr);
 }
 
-int mutex_create (int mutex_rid) { return do_syscall (SYS_MUTEX_CREATE, mutex_rid); }
+int mutex_create (void) { return do_syscall (SYS_MUTEX_CREATE, 0); }
 
 int mutex_delete (int mutex_rid) { return do_syscall (SYS_MUTEX_DELETE, mutex_rid); }
 
diff --git a/libsystem/system.h b/libsystem/system.h
index f84fa79..fd4bec6 100644
--- a/libsystem/system.h
+++ b/libsystem/system.h
@@ -33,7 +33,7 @@ int unmap (uintptr_t vaddr, size_t pages);
 int clone (uintptr_t vstack_top, void (*entry) (void), void* argument_ptr);
 
 /* Create a mutex */
-int mutex_create (int mutex_rid);
+int mutex_create (void);
 
 /* Delete a mutex. Will wake up waiters */
 int mutex_delete (int mutex_rid);