diff --git a/include/uc_priv.h b/include/uc_priv.h
index 686ab9e5..7e76513a 100644
--- a/include/uc_priv.h
+++ b/include/uc_priv.h
@@ -47,6 +47,8 @@ typedef void (*uc_args_uc_u64_t)(struct uc_struct *, uint64_t addr);
 
 typedef MemoryRegion* (*uc_args_uc_ram_size_t)(struct uc_struct*,  ram_addr_t begin, size_t size, uint32_t perms);
 
+typedef void (*uc_mem_unmap_t)(struct uc_struct*, MemoryRegion *mr);
+
 typedef void (*uc_readonly_mem_t)(MemoryRegion *mr, bool readonly);
 
 // which interrupt should make emulation stop?
@@ -90,6 +92,7 @@ struct uc_struct {
     uc_args_tcg_enable_t tcg_enabled;
     uc_args_uc_long_t tcg_exec_init;
     uc_args_uc_ram_size_t memory_map;
+    uc_mem_unmap_t memory_unmap;
     uc_readonly_mem_t readonly_mem;
     // list of cpu
     void* cpu;
diff --git a/include/unicorn/unicorn.h b/include/unicorn/unicorn.h
index 991db568..fee75297 100644
--- a/include/unicorn/unicorn.h
+++ b/include/unicorn/unicorn.h
@@ -422,9 +422,9 @@ uc_err uc_mem_map(uch handle, uint64_t address, size_t size, uint32_t perms);
  This API changes permissions on an existing memory region.
 
  @handle: handle returned by uc_open()
- @start: starting address of the memory region to be modified.
+ @address: starting address of the memory region to be modified.
     This address must be aligned to 4KB, or this will return with UC_ERR_MAP error.
- @block_size: size of the memory region to be modified.
+ @size: size of the memory region to be modified.
     This size must be multiple of 4KB, or this will return with UC_ERR_MAP error.
  @perms: New permissions for the mapped region.
     This must be some combination of UC_PROT_READ | UC_PROT_WRITE | UC_PROT_EXEC,
@@ -434,7 +434,23 @@ uc_err uc_mem_map(uch handle, uint64_t address, size_t size, uint32_t perms);
  for detailed error).
 */
 UNICORN_EXPORT
-uc_err uc_mem_protect(uch handle, uint64_t start, size_t block_size, uint32_t perms);
+uc_err uc_mem_protect(uch handle, uint64_t address, size_t size, uint32_t perms);
+
+/*
+ Unmap a region of emulation memory.
+ This API deletes a memory mapping from the emulation memory space.
+
+ @handle: handle returned by uc_open()
+ @address: starting address of the memory region to be unmapped.
+    This address must be aligned to 4KB, or this will return with UC_ERR_MAP error.
+ @size: size of the memory region to be modified.
+    This size must be multiple of 4KB, or this will return with UC_ERR_MAP error.
+
+ @return UC_ERR_OK on success, or other value on failure (refer to uc_err enum
+ for detailed error).
+*/
+UNICORN_EXPORT
+uc_err uc_mem_unmap(uch handle, uint64_t address, size_t size);
 
 #ifdef __cplusplus
 }
diff --git a/qemu/aarch64.h b/qemu/aarch64.h
index 9ab06273..77de1644 100644
--- a/qemu/aarch64.h
+++ b/qemu/aarch64.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_aarch64
 #define tb_cleanup tb_cleanup_aarch64
 #define memory_map memory_map_aarch64
+#define memory_unmap memory_unmap_aarch64
 #define memory_free memory_free_aarch64
 #define helper_raise_exception helper_raise_exception_aarch64
 #define tcg_enabled tcg_enabled_aarch64
diff --git a/qemu/arm.h b/qemu/arm.h
index c24329b3..3d405fac 100644
--- a/qemu/arm.h
+++ b/qemu/arm.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_arm
 #define tb_cleanup tb_cleanup_arm
 #define memory_map memory_map_arm
+#define memory_unmap memory_unmap_arm
 #define memory_free memory_free_arm
 #define helper_raise_exception helper_raise_exception_arm
 #define tcg_enabled tcg_enabled_arm
diff --git a/qemu/header_gen.py b/qemu/header_gen.py
index ff8a1ca5..67982502 100644
--- a/qemu/header_gen.py
+++ b/qemu/header_gen.py
@@ -13,6 +13,7 @@ symbols = (
     'phys_mem_clean',
     'tb_cleanup',
     'memory_map',
+    'memory_unmap',
     'memory_free',
     'helper_raise_exception',
     'tcg_enabled',
diff --git a/qemu/include/exec/memory.h b/qemu/include/exec/memory.h
index 4df8bd85..45c51e4d 100644
--- a/qemu/include/exec/memory.h
+++ b/qemu/include/exec/memory.h
@@ -939,6 +939,7 @@ void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
 void memory_register_types(struct uc_struct *uc);
 
 MemoryRegion *memory_map(struct uc_struct *uc, ram_addr_t begin, size_t size, uint32_t perms);
+void memory_unmap(struct uc_struct *uc, MemoryRegion *mr);
 int memory_free(struct uc_struct *uc);
 
 #endif
diff --git a/qemu/m68k.h b/qemu/m68k.h
index 5dbefab7..4be757ba 100644
--- a/qemu/m68k.h
+++ b/qemu/m68k.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_m68k
 #define tb_cleanup tb_cleanup_m68k
 #define memory_map memory_map_m68k
+#define memory_unmap memory_unmap_m68k
 #define memory_free memory_free_m68k
 #define helper_raise_exception helper_raise_exception_m68k
 #define tcg_enabled tcg_enabled_m68k
diff --git a/qemu/memory.c b/qemu/memory.c
index 3f8169d9..95336f5f 100644
--- a/qemu/memory.c
+++ b/qemu/memory.c
@@ -45,6 +45,18 @@ MemoryRegion *memory_map(struct uc_struct *uc, ram_addr_t begin, size_t size, ui
     return uc->ram;
 }
 
+void memory_unmap(struct uc_struct *uc, MemoryRegion *mr)
+{
+    targer_ulong addr;
+    //make sure all pages associated with the MemoryRegion are flushed
+    for (addr = mr->addr; addr < mr->end; addr += 0x1000) {
+       tlb_flush_page(uc->current_cpu, addr);
+    }
+    mr->enabled = false;
+    memory_region_del_subregion(get_system_memory(uc), mr);
+    g_free(mr);
+}
+
 int memory_free(struct uc_struct *uc)
 {
     int i;
diff --git a/qemu/mips.h b/qemu/mips.h
index 059995e5..7a3e308a 100644
--- a/qemu/mips.h
+++ b/qemu/mips.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_mips
 #define tb_cleanup tb_cleanup_mips
 #define memory_map memory_map_mips
+#define memory_unmap memory_unmap_mips
 #define memory_free memory_free_mips
 #define helper_raise_exception helper_raise_exception_mips
 #define tcg_enabled tcg_enabled_mips
diff --git a/qemu/mips64.h b/qemu/mips64.h
index 74daddbc..9870cb15 100644
--- a/qemu/mips64.h
+++ b/qemu/mips64.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_mips64
 #define tb_cleanup tb_cleanup_mips64
 #define memory_map memory_map_mips64
+#define memory_unmap memory_unmap_mips64
 #define memory_free memory_free_mips64
 #define helper_raise_exception helper_raise_exception_mips64
 #define tcg_enabled tcg_enabled_mips64
diff --git a/qemu/mips64el.h b/qemu/mips64el.h
index 6ffc2dbc..5fde9e53 100644
--- a/qemu/mips64el.h
+++ b/qemu/mips64el.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_mips64el
 #define tb_cleanup tb_cleanup_mips64el
 #define memory_map memory_map_mips64el
+#define memory_unmap memory_unmap_mips64el
 #define memory_free memory_free_mips64el
 #define helper_raise_exception helper_raise_exception_mips64el
 #define tcg_enabled tcg_enabled_mips64el
diff --git a/qemu/mipsel.h b/qemu/mipsel.h
index 94c4fdf7..caf1fe4d 100644
--- a/qemu/mipsel.h
+++ b/qemu/mipsel.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_mipsel
 #define tb_cleanup tb_cleanup_mipsel
 #define memory_map memory_map_mipsel
+#define memory_unmap memory_unmap_mipsel
 #define memory_free memory_free_mipsel
 #define helper_raise_exception helper_raise_exception_mipsel
 #define tcg_enabled tcg_enabled_mipsel
diff --git a/qemu/powerpc.h b/qemu/powerpc.h
index fd627665..92e614e1 100644
--- a/qemu/powerpc.h
+++ b/qemu/powerpc.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_powerpc
 #define tb_cleanup tb_cleanup_powerpc
 #define memory_map memory_map_powerpc
+#define memory_unmap memory_unmap_powerpc
 #define memory_free memory_free_powerpc
 #define helper_raise_exception helper_raise_exception_powerpc
 #define tcg_enabled tcg_enabled_powerpc
diff --git a/qemu/sparc.h b/qemu/sparc.h
index 64803c11..6aa47aa5 100644
--- a/qemu/sparc.h
+++ b/qemu/sparc.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_sparc
 #define tb_cleanup tb_cleanup_sparc
 #define memory_map memory_map_sparc
+#define memory_unmap memory_unmap_sparc
 #define memory_free memory_free_sparc
 #define helper_raise_exception helper_raise_exception_sparc
 #define tcg_enabled tcg_enabled_sparc
diff --git a/qemu/sparc64.h b/qemu/sparc64.h
index 5042c38d..6d3d2a1d 100644
--- a/qemu/sparc64.h
+++ b/qemu/sparc64.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_sparc64
 #define tb_cleanup tb_cleanup_sparc64
 #define memory_map memory_map_sparc64
+#define memory_unmap memory_unmap_sparc64
 #define memory_free memory_free_sparc64
 #define helper_raise_exception helper_raise_exception_sparc64
 #define tcg_enabled tcg_enabled_sparc64
diff --git a/qemu/unicorn_common.h b/qemu/unicorn_common.h
index 176900cb..23ef0acb 100644
--- a/qemu/unicorn_common.h
+++ b/qemu/unicorn_common.h
@@ -73,6 +73,7 @@ static inline void uc_common_init(struct uc_struct* uc)
     uc->pause_all_vcpus = pause_all_vcpus;
     uc->vm_start = vm_start;
     uc->memory_map = memory_map;
+    uc->memory_unmap = memory_unmap;
     uc->readonly_mem = memory_region_set_readonly;
 
     if (!uc->release)
diff --git a/qemu/x86_64.h b/qemu/x86_64.h
index 9a148e95..ac9f34f0 100644
--- a/qemu/x86_64.h
+++ b/qemu/x86_64.h
@@ -7,6 +7,7 @@
 #define phys_mem_clean phys_mem_clean_x86_64
 #define tb_cleanup tb_cleanup_x86_64
 #define memory_map memory_map_x86_64
+#define memory_unmap memory_unmap_x86_64
 #define memory_free memory_free_x86_64
 #define helper_raise_exception helper_raise_exception_x86_64
 #define tcg_enabled tcg_enabled_x86_64
diff --git a/uc.c b/uc.c
index 3c46e689..ec85ea61 100644
--- a/uc.c
+++ b/uc.c
@@ -643,87 +643,130 @@ uc_err uc_mem_map(uch handle, uint64_t address, size_t size, uint32_t perms)
 }
 
 UNICORN_EXPORT
-uc_err uc_mem_protect(uch handle, uint64_t start, size_t block_size, uint32_t perms)
+uc_err uc_mem_protect(uch handle, uint64_t address, size_t size, uint32_t perms)
 {
-    uint64_t address;
-    uint64_t size;
     struct uc_struct* uc = (struct uc_struct *)handle;
+    MemoryRegion *mr;
 
     if (handle == 0)
         // invalid handle
         return UC_ERR_UCH;
 
-    if (block_size == 0)
+    if (size == 0)
         // invalid memory mapping
         return UC_ERR_MAP;
 
     // address must be aligned to 4KB
-    if ((start & (4*1024 - 1)) != 0)
+    if ((address & (4*1024 - 1)) != 0)
         return UC_ERR_MAP;
 
     // size must be multiple of 4KB
-    if ((block_size & (4*1024 - 1)) != 0)
+    if ((size & (4*1024 - 1)) != 0)
         return UC_ERR_MAP;
 
     // check for only valid permissions
     if ((perms & ~(UC_PROT_READ | UC_PROT_WRITE | UC_PROT_EXEC)) != 0)
         return UC_ERR_MAP;
         
-    //check that users entire requested block is mapped
-    address = start;
-    size = block_size;
-    while (size > 0) {
-        uint64_t region_size;
-        MemoryRegion *mr = memory_mapping(uc, address);
-        if (mr == NULL) {
-            return UC_ERR_MAP;
-        }
-        region_size = int128_get64(mr->size);
-        if (address > mr->addr) {
-            //in case start address is not aligned with start of region
-            region_size -= address - mr->addr;
-        }
-        if (size < region_size) {
-            //entire region is covered
-            break;
-        }
-        size -= region_size;
-        address += region_size;
-    }
+    //check that user's entire requested block is mapped
+    if (!check_mem_area(uc, address, size))
+        return UC_ERR_MAP;
 
     //Now we know entire region is mapped, so change permissions
-    address = start;
-    size = block_size;
-    while (size > 0) {
-        MemoryRegion *mr = memory_mapping(uc, address);
-        uint64_t region_size = int128_get64(mr->size);
-        if (address > mr->addr) {
-            //in case start address is not aligned with start of region
-            region_size -= address - mr->addr;
-            //TODO Learn how to split regions
-            //In this case some proper subset of the region is having it's permissions changed
-            //need to split region and add new portions into uc->mapped_blocks list
-            //In this case, there is a portion of the region with original perms: mr->addr..start
-            //and a portion getting new perms: start..start+block_size
-
-            //split the block and stay in the loop
-        }
-        if (size < int128_get64(mr->size)) {
-            //TODO Learn how to split regions
-            //In this case some proper subset of the region is having it's permissions changed
-            //need to split region and add new portions into uc->mapped_blocks list
-            //In this case, there is a portion of the region with new perms: start..start+block_size
-            //and a portion getting new perms: mr->addr+size..mr->addr+mr->size
-
-            //split the block and break
-            break;
-        }
-        size -= int128_get64(mr->size);
-        address += int128_get64(mr->size);
+    //check trivial case first
+    mr = memory_mapping(uc, address);
+    if (address == mr->addr && size == int128_get64(mr->size)) {
+        //regions exactly matches an existing region just change perms
         mr->perms = perms;
         uc->readonly_mem(mr, (perms & UC_PROT_WRITE) == 0);
     }
-    return UC_ERR_OK;
+    else {
+        //ouch, we are going to need to subdivide blocks
+/*
+        address = start;
+        size = block_size;
+        while (size > 0) {
+            MemoryRegion *mr = memory_mapping(uc, address);
+            uint64_t region_size = int128_get64(mr->size);
+            if (address > mr->addr) {
+                //in case start address is not aligned with start of region
+                region_size -= address - mr->addr;
+                //TODO Learn how to split regions
+                //In this case some proper subset of the region is having it's permissions changed
+                //need to split region and add new portions into uc->mapped_blocks list
+                //In this case, there is a portion of the region with original perms: mr->addr..start
+                //and a portion getting new perms: start..start+block_size
+    
+                //split the block and stay in the loop
+            }
+            if (size < int128_get64(mr->size)) {
+                //TODO Learn how to split regions
+                //In this case some proper subset of the region is having it's permissions changed
+                //need to split region and add new portions into uc->mapped_blocks list
+                //In this case, there is a portion of the region with new perms: start..start+block_size
+                //and a portion getting new perms: mr->addr+size..mr->addr+mr->size
+    
+                //split the block and break
+                break;
+            }
+            size -= int128_get64(mr->size);
+            address += int128_get64(mr->size);
+            mr->perms = perms;
+            uc->readonly_mem(mr, (perms & UC_PROT_WRITE) == 0);
+        }
+*/
+     }
+     return UC_ERR_OK;
+}
+
+UNICORN_EXPORT
+uc_err uc_mem_unmap(uch handle, uint64_t address, size_t size)
+{
+    MemoryRegion *mr;
+    unsigned int i;
+    struct uc_struct* uc = (struct uc_struct *)handle;
+
+    if (handle == 0)
+        // invalid handle
+        return UC_ERR_UCH;
+
+    if (size == 0)
+        // nothing to unmap
+        return UC_ERR_OK;
+
+    // address must be aligned to 4KB
+    if ((address & (4*1024 - 1)) != 0)
+        return UC_ERR_MAP;
+
+    // size must be multiple of 4KB
+    if ((size & (4*1024 - 1)) != 0)
+        return UC_ERR_MAP;
+
+    //check that user's entire requested block is mapped
+    if (!check_mem_area(uc, address, size))
+        return UC_ERR_MAP;
+
+    //Now we know entire region is mapped, so change permissions
+    //check trivial case first
+    mr = memory_mapping(uc, address);
+    if (address == mr->addr && size == int128_get64(mr->size)) {
+        //regions exactly matches an existing region just unmap it
+        uc->memory_unmap(uc, mr);
+        for (i = 0; i < uc->mapped_block_count; i++) {
+            if (uc->mapped_blocks[i] == mr) {
+                uc->mapped_block_count--;
+                //shift remainder of array down over deleted pointer
+                memcpy(&uc->mapped_blocks[i], &uc->mapped_blocks[i + 1], sizeof(MemoryRegion*) * (uc->mapped_block_count - i));
+                break;
+            }
+        }
+        return UC_ERR_OK;
+     }
+    else {
+        //ouch, we are going to need to subdivide blocks
+    }
+
+    return UC_ERR_MAP;
 }
 
 MemoryRegion *memory_mapping(struct uc_struct* uc, uint64_t address)