diff --git a/debian/changelog b/debian/changelog
index 11797cd4..9001e46a 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,5 +1,6 @@
-llvm-toolchain-3.8 (1:3.8.1-11) UNRELEASED; urgency=medium
+llvm-toolchain-3.8 (1:3.8.1-11) unstable; urgency=medium
 
+  * Fix the arm64 lldb build issue. Thanks to Ximin Luo (Closes: #836591)
   * Fix asan with libc6 >= 2.24 (asan-glibc-2.24.diff, backport of 269633)
     Many thanks to Michael Stapelberg for the great bug report.
     (Closes: 836723)
diff --git a/debian/patches/lldb-dont-assume-64bit-systems-are-all-x86-64.patch b/debian/patches/lldb-dont-assume-64bit-systems-are-all-x86-64.patch
new file mode 100644
index 00000000..366f5331
--- /dev/null
+++ b/debian/patches/lldb-dont-assume-64bit-systems-are-all-x86-64.patch
@@ -0,0 +1,18 @@
+Index: llvm-toolchain-3.8-3.8.1/lldb/cmake/modules/LLDBConfig.cmake
+===================================================================
+--- llvm-toolchain-3.8-3.8.1.orig/lldb/cmake/modules/LLDBConfig.cmake
++++ llvm-toolchain-3.8-3.8.1/lldb/cmake/modules/LLDBConfig.cmake
+@@ -165,13 +165,6 @@ function(find_python_libs_windows)
+ endfunction(find_python_libs_windows)
+ 
+ if (NOT LLDB_DISABLE_PYTHON)
+-  if(UNIX)
+-    # This is necessary for crosscompile on Ubuntu 14.04 64bit. Need a proper fix.
+-    if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+-      set(CMAKE_LIBRARY_ARCHITECTURE "x86_64-linux-gnu")
+-    endif()
+-  endif()
+-
+   if ("${CMAKE_SYSTEM_NAME}" STREQUAL "Windows")
+     find_python_libs_windows()
+ 
diff --git a/debian/patches/series b/debian/patches/series
index 763936d6..1d90a2a3 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -46,3 +46,4 @@ D17567-PR23529-Sema-part-of-attrbute-abi_tag-support.diff
 D18035-PR23529-Mangler-part-of-attrbute-abi_tag-support.diff
 kfreebsd-support.diff
 asan-glibc-2.24.diff
+lldb-dont-assume-64bit-systems-are-all-x86-64.patch