diff --git a/arch/x86/pagetables.c b/arch/x86/pagetables.c
index 453f7ba7..6ad870b9 100644
--- a/arch/x86/pagetables.c
+++ b/arch/x86/pagetables.c
@@ -23,6 +23,7 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include <console.h>
+#include <errno.h>
 #include <ktf.h>
 #include <multiboot2.h>
 #include <page.h>
@@ -279,6 +280,88 @@ static void map_tmp_mapping_entry(void) {
     _tmp_mapping_entry = paddr_to_virt_kern(_paddr(entry));
 }
 
+static int _vunmap(cr3_t *cr3_ptr, void *va, mfn_t *mfn, unsigned int *order) {
+    pgentry_t *tab;
+    mfn_t _mfn;
+    unsigned int _order;
+    pgentry_t *entry;
+    bool present;
+
+    if (mfn_invalid(cr3_ptr->mfn))
+        return -EINVAL;
+
+    dprintk("%s: va: 0x%p (cr3: 0x%p)\n", __func__, va, cr3_ptr);
+
+    tab = tmp_map_mfn(cr3_ptr->mfn);
+#if defined(__x86_64__)
+    pml4_t *l4e = l4_table_entry((pml4_t *) tab, va);
+    if (mfn_invalid(l4e->mfn) || !l4e->P)
+        return -ENOENT;
+
+    tab = tmp_map_mfn(l4e->mfn);
+#endif
+    pdpe_t *l3e = l3_table_entry((pdpe_t *) tab, va);
+    if (l3e->PS) {
+        _mfn = l3e->mfn;
+        _order = PAGE_ORDER_1G;
+        entry = &l3e->entry;
+        present = l3e->P;
+        goto done;
+    }
+
+    if (mfn_invalid(l3e->mfn) || !l3e->P)
+        return -ENOENT;
+
+    tab = tmp_map_mfn(l3e->mfn);
+    pde_t *l2e = l2_table_entry((pde_t *) tab, va);
+    if (l2e->PS) {
+        _mfn = l2e->mfn;
+        _order = PAGE_ORDER_2M;
+        entry = &l2e->entry;
+        present = l2e->P;
+        goto done;
+    }
+
+    if (mfn_invalid(l2e->mfn) || !l2e->P)
+        return -ENOENT;
+
+    tab = tmp_map_mfn(l2e->mfn);
+    pte_t *l1e = l1_table_entry((pte_t *) tab, va);
+    _mfn = l1e->mfn;
+    _order = PAGE_ORDER_4K;
+    entry = &l1e->entry;
+    present = l1e->P;
+
+done:
+    if (mfn)
+        *mfn = _mfn;
+    if (order)
+        *order = _order;
+    set_pgentry(entry, MFN_INVALID, PT_NO_FLAGS);
+    if (present)
+        invlpg(va);
+
+    return 0;
+}
+
+int vunmap_kern(void *va, mfn_t *mfn, unsigned int *order) {
+    int err;
+
+    spin_lock(&vmap_lock);
+    err = _vunmap(&cr3, va, mfn, order);
+    spin_unlock(&vmap_lock);
+    return err;
+}
+
+int vunmap_user(void *va, mfn_t *mfn, unsigned int *order) {
+    int err;
+
+    spin_lock(&vmap_lock);
+    err = _vunmap(&user_cr3, va, mfn, order);
+    spin_unlock(&vmap_lock);
+    return err;
+}
+
 static inline void init_cr3(cr3_t *cr3_ptr) {
     memset(cr3_ptr, 0, sizeof(*cr3_ptr));
     cr3_ptr->mfn = MFN_INVALID;
diff --git a/common/acpi.c b/common/acpi.c
index d4f19de7..9cd7eb43 100644
--- a/common/acpi.c
+++ b/common/acpi.c
@@ -155,7 +155,7 @@ static void acpi_table_unmap_pages(void *addr, unsigned mapped_pages) {
     mfn_t mfn = virt_to_mfn(addr);
 
     for (unsigned i = 0; i < mapped_pages; i++, mfn++) {
-        vunmap_kern(mfn_to_virt_kern(mfn), PAGE_ORDER_4K);
+        vunmap_kern(mfn_to_virt_kern(mfn), NULL, NULL);
     }
 }
 
diff --git a/common/setup.c b/common/setup.c
index ae0ec70e..40d9e588 100644
--- a/common/setup.c
+++ b/common/setup.c
@@ -117,10 +117,19 @@ static __always_inline void zero_bss(void) {
 void zap_boot_mappings(void) {
     for_each_memory_range (r) {
         if (r->base == VIRT_IDENT_BASE && IS_INIT_SECTION(r->name)) {
+            unsigned int order = PAGE_ORDER_4K;
+
             memset(r->start, 0, r->end - r->start);
-            for (mfn_t mfn = virt_to_mfn(r->start); mfn < virt_to_mfn(r->end); mfn++) {
-                vunmap_kern(mfn_to_virt(mfn), PAGE_ORDER_4K);
-                reclaim_frame(mfn, PAGE_ORDER_4K);
+            for (void *va = r->start; va < r->end; va += ORDER_TO_SIZE(order)) {
+                mfn_t mfn;
+
+                if (vunmap_kern(va, &mfn, &order)) {
+                    /* FIXME: Use warning */
+                    printk("Unable to unmap kernel boot mapping at %p\n", va);
+                    order = PAGE_ORDER_4K;
+                    continue;
+                }
+                reclaim_frame(mfn, order);
             }
         }
     }
diff --git a/common/usermode.c b/common/usermode.c
index 8a0d311e..5ad8d6aa 100644
--- a/common/usermode.c
+++ b/common/usermode.c
@@ -61,9 +61,15 @@ long syscall_handler(long syscall_nr, long arg1, long arg2, long arg3, long arg4
 
     case SYSCALL_MUNMAP: {
         void *va = _ptr(arg1);
-        unsigned int order = _u(arg2);
+        mfn_t mfn;
+        unsigned int order;
+        int err;
+
+        err = vunmap_user(va, &mfn, &order);
+        if (err)
+            return err;
 
-        vunmap_user(va, order);
+        put_free_frames(mfn, order);
         return 0;
     }
 
@@ -217,8 +223,8 @@ static inline long __user_text sys_mmap(void *va, unsigned long order) {
     return syscall2(SYSCALL_MMAP, _ul(va), order);
 }
 
-static inline long __user_text sys_munmap(void *va, unsigned long order) {
-    return syscall2(SYSCALL_MUNMAP, _ul(va), order);
+static inline long __user_text sys_munmap(void *va) {
+    return syscall1(SYSCALL_MUNMAP, _ul(va));
 }
 
 void __user_text exit(unsigned long exit_code) {
@@ -237,6 +243,6 @@ void *__user_text mmap(void *va, unsigned long order) {
     return _ptr(sys_mmap(va, order));
 }
 
-void __user_text munmap(void *va, unsigned long order) {
-    sys_munmap(va, order);
+int __user_text munmap(void *va) {
+    return sys_munmap(va);
 }
diff --git a/drivers/acpi/acpica/osl.c b/drivers/acpi/acpica/osl.c
index 674d0dd4..32059f17 100644
--- a/drivers/acpi/acpica/osl.c
+++ b/drivers/acpi/acpica/osl.c
@@ -338,7 +338,7 @@ void AcpiOsUnmapMemory(void *LogicalAddress, ACPI_SIZE Length) {
         if (--frame->refcount > 0)
             continue;
 
-        vunmap_kern(mfn_to_virt_map(mfn), PAGE_ORDER_4K);
+        vunmap_kern(mfn_to_virt_map(mfn), NULL, NULL);
         list_unlink(&frame->list);
         kfree(frame);
     }
diff --git a/include/arch/x86/page.h b/include/arch/x86/page.h
index 76beb5b9..64835bf4 100644
--- a/include/arch/x86/page.h
+++ b/include/arch/x86/page.h
@@ -175,6 +175,8 @@ extern void *vmap_user(void *va, mfn_t mfn, unsigned int order,
                        unsigned long l3_flags, unsigned long l2_flags,
                        unsigned long l1_flags);
 
+extern int vunmap_kern(void *va, mfn_t *mfn, unsigned int *order);
+extern int vunmap_user(void *va, mfn_t *mfn, unsigned int *order);
 extern void pat_set_type(pat_field_t field, pat_memory_type_t type);
 extern pat_memory_type_t pat_get_type(pat_field_t field);
 
@@ -241,14 +243,6 @@ static inline mfn_t virt_to_mfn(const void *va) {
     return paddr_to_mfn(virt_to_paddr(va));
 }
 
-static inline void vunmap_kern(void *va, unsigned int order) {
-    vmap_kern(va, MFN_INVALID, order, PT_NO_FLAGS, PT_NO_FLAGS, PT_NO_FLAGS, PT_NO_FLAGS);
-}
-
-static inline void vunmap_user(void *va, unsigned int order) {
-    vmap_user(va, MFN_INVALID, order, PT_NO_FLAGS, PT_NO_FLAGS, PT_NO_FLAGS, PT_NO_FLAGS);
-}
-
 static inline void *kmap(mfn_t mfn, unsigned int order,
 #if defined(__x86_64__)
                          unsigned long l4_flags,
diff --git a/include/mm/vmm.h b/include/mm/vmm.h
index 114d4117..3d14b4e8 100644
--- a/include/mm/vmm.h
+++ b/include/mm/vmm.h
@@ -38,7 +38,7 @@ typedef enum gfp_flags gfp_flags_t;
 /* External definitions */
 
 extern void *get_free_pages(unsigned int order, gfp_flags_t flags);
-extern void put_pages(void *page, unsigned int order);
+extern void put_pages(void *page);
 
 /* Static definitions */
 
@@ -55,11 +55,11 @@ static inline void *get_free_page_top(gfp_flags_t flags) {
 }
 
 static inline void put_page(void *page) {
-    put_pages(page, PAGE_ORDER_4K);
+    put_pages(page);
 }
 
 static inline void put_page_top(void *page) {
-    put_pages(page - PAGE_SIZE, PAGE_ORDER_4K);
+    put_pages(page - PAGE_SIZE);
 }
 
 #endif /* KTF_VMM_H */
diff --git a/include/usermode.h b/include/usermode.h
index 9f41145a..40bc133b 100644
--- a/include/usermode.h
+++ b/include/usermode.h
@@ -64,7 +64,7 @@ extern void init_usermode(percpu_t *percpu);
 extern void __user_text exit(unsigned long exit_code);
 extern void __user_text printf(const char *fmt, ...);
 extern void *__user_text mmap(void *va, unsigned long order);
-extern void __user_text munmap(void *va, unsigned long order);
+extern int __user_text munmap(void *va);
 extern bool __user_text syscall_mode(syscall_mode_t);
 
 #endif /* __ASSEMBLY__ */
diff --git a/mm/slab.c b/mm/slab.c
index 1072af95..bcec130f 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -155,7 +155,7 @@ meta_slab_t *slab_meta_alloc() {
     ret = initialize_slab(meta_slab_page);
     if (ret != ESUCCESS) {
         dprintk("initialize_slab in slab_meta_alloc failed\n");
-        put_pages(free_page, PAGE_ORDER_4K);
+        put_pages(free_page);
         return NULL;
     }
 
@@ -246,7 +246,7 @@ static void *ktf_alloc(size_t size) {
 
     if (ret != ESUCCESS) {
         dprintk("initialize_slab failed\n");
-        put_pages(free_page, PAGE_ORDER_4K);
+        put_pages(free_page);
         alloc = NULL;
         goto out;
     }
@@ -297,7 +297,7 @@ static void ktf_free(void *ptr) {
                      * meta slab free
                      */
                     list_unlink(&slab->list);
-                    put_pages(slab->slab_base, PAGE_ORDER_4K);
+                    put_pages(slab->slab_base);
                     meta_slab_page = META_SLAB_PAGE_ENTRY(slab);
                     slab_free(meta_slab_page, slab);
                     /*
@@ -311,7 +311,7 @@ static void ktf_free(void *ptr) {
                                 meta_slab_page->slab_base);
                         list_unlink(&meta_slab_page->list);
                         memset(meta_slab_page, 0, PAGE_SIZE);
-                        put_pages(meta_slab_page, PAGE_ORDER_4K);
+                        put_pages(meta_slab_page);
                     }
                 }
                 spin_unlock(&slab_mm_lock);
diff --git a/mm/vmm.c b/mm/vmm.c
index 6bc64a87..53d8562a 100644
--- a/mm/vmm.c
+++ b/mm/vmm.c
@@ -81,10 +81,12 @@ void *get_free_pages(unsigned int order, gfp_flags_t flags) {
     return va;
 }
 
-void put_pages(void *page, unsigned int order) {
-    /* FIXME: unmap all mappings */
+void put_pages(void *page) {
+    unsigned int order;
+    mfn_t mfn;
+
     spin_lock(&mmap_lock);
-    vunmap_kern(page, order);
-    put_free_frames(virt_to_mfn(page), order);
+    BUG_ON(vunmap_kern(page, &mfn, &order));
+    put_free_frames(mfn, order);
     spin_unlock(&mmap_lock);
 }
\ No newline at end of file
diff --git a/tests/unittests.c b/tests/unittests.c
index 8a6c379c..82d114b8 100644
--- a/tests/unittests.c
+++ b/tests/unittests.c
@@ -98,7 +98,12 @@ static unsigned long __user_text test_user_task_func2(void *arg) {
 
     va = mmap(_ptr(0xfff80000), PAGE_ORDER_4K);
     printf(USTR("mmap: %lx\n"), _ul(va));
+    if (munmap(va) != 0) {
+        printf(USTR("ERROR: munmap failed\n"));
+        ud2();
+    }
 
+    va = mmap(_ptr(0xfff80000), PAGE_ORDER_4K);
     memset(va, 0xcc, 0x1000);
     ((void (*)(void)) va)();