diff --git a/.gitmodules b/.gitmodules
index 4c8a5f6edb4..f8fca965e9d 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -20,7 +20,7 @@
 [submodule "external/libzip"]
 	path = external/libzip
 	url = https://github.com/nih-at/libzip.git
-	branch = master
+	branch = rel-1-5-1
 [submodule "external/LibZipSharp"]
 	path = external/LibZipSharp
 	url = https://github.com/grendello/LibZipSharp.git
diff --git a/Makefile b/Makefile
index ee38f21a10e..312dff097a2 100644
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,10 @@ SOLUTION      = Xamarin.Android.sln
 TEST_TARGETS  = build-tools/scripts/RunTests.targets
 API_LEVEL     ?=
 
+ifeq ($(OS_NAME),Darwin)
+export MACOSX_DEPLOYMENT_TARGET := 10.11
+endif
+
 ifneq ($(V),0)
 MONO_OPTIONS += --debug
 endif
diff --git a/external/LibZipSharp b/external/LibZipSharp
index b7aab1e26ae..4d3e59c8960 160000
--- a/external/LibZipSharp
+++ b/external/LibZipSharp
@@ -1 +1 @@
-Subproject commit b7aab1e26aed3e0269a73cc6f8ce973169741f76
+Subproject commit 4d3e59c8960562309c817a4c367300e6a20bf9b7
diff --git a/external/libzip b/external/libzip
index 1d8b1ac4d20..b95cf3fdd4c 160000
--- a/external/libzip
+++ b/external/libzip
@@ -1 +1 @@
-Subproject commit 1d8b1ac4d20b8ef8d3f5d496dabebaa0ff9019ff
+Subproject commit b95cf3fdd4c1271f922017f092d02a878873425c
diff --git a/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.ProjectTools/Xamarin.ProjectTools.Darwin.projitems b/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.ProjectTools/Xamarin.ProjectTools.Darwin.projitems
index 57a40ae6976..e316e8bb019 100644
--- a/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.ProjectTools/Xamarin.ProjectTools.Darwin.projitems
+++ b/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.ProjectTools/Xamarin.ProjectTools.Darwin.projitems
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" ?>
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup>
-    <Content Include="$(XAInstallPrefix)xbuild\Xamarin\Android\libzip.3.0.dylib">
+    <Content Include="$(XAInstallPrefix)xbuild\Xamarin\Android\libzip.5.0.dylib">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
   </ItemGroup>
diff --git a/src/libzip-windows/libzip-windows.csproj b/src/libzip-windows/libzip-windows.csproj
index 647f42326b0..648df6500d0 100644
--- a/src/libzip-windows/libzip-windows.csproj
+++ b/src/libzip-windows/libzip-windows.csproj
@@ -16,7 +16,7 @@
   </PropertyGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.Common.targets" />
   <PropertyGroup>
-    <BuildDependsOnLocal Condition=" '$(HostOS)' == 'Darwin' ">
+    <BuildDependsOnLocal Condition=" '$(HostOS)' == 'Darwin' Or '$(HostOS)' == 'Linux' ">
       ResolveReferences;
       _BuildUnlessCached
     </BuildDependsOnLocal>
diff --git a/src/libzip-windows/libzip-windows.projitems b/src/libzip-windows/libzip-windows.projitems
index f77d1cab3f1..712077bccbd 100644
--- a/src/libzip-windows/libzip-windows.projitems
+++ b/src/libzip-windows/libzip-windows.projitems
@@ -1,15 +1,28 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup Condition=" '$(HostOS)' == 'Linux' ">
+    <CMakeBinary32>\usr\bin\cmake</CMakeBinary32>
+    <CMakeBinary64>$(CMakeBinary32)</CMakeBinary64>
+    <CMakeFlags32>-DCMAKE_TOOLCHAIN_FILE=$(MSBuildThisFileDirectory)\mingw-linux-32.cmake</CMakeFlags32>
+    <CMakeFlags64>-DCMAKE_TOOLCHAIN_FILE=$(MSBuildThisFileDirectory)\mingw-linux-64.cmake</CMakeFlags64>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(HostOS)' == 'Darwin' ">
+    <CMakeBinary64>cmake</CMakeBinary64>
+    <CMakeBinary32>cmake</CMakeBinary32>
+    <CMakeCommonFlags>-DCMAKE_SYSTEM_NAME=Windows -DCMAKE_FIND_ROOT_PATH_MODE_PROGRAM=NEVER -DCMAKE_FIND_ROOT_PATH_MODE_LIBRARY=ONLY -DCMAKE_FIND_ROOT_PATH_MODE_INCLUDE=ONLY -DCMAKE_WINDOWS_EXPORT_ALL_SYMBOLS=ON -DBUILD_SHARED_LIBS=ON</CMakeCommonFlags>
+    <CMakeFlags32>$(CMakeCommonFlags) -DCMAKE_C_COMPILER=$(AndroidMxeFullPath)\bin\$(MingwCommandPrefix32)-gcc -DCMAKE_CXX_COMPILER=$(AndroidMxeFullPath)\bin\$(MingwCommandPrefix32)-g++ -DCMAKE_RC_COMPILER=$(AndroidMxeFullPath)\bin\$(MingwCommandPrefix32)-windres -DCMAKE_FIND_ROOT_PATH=$(AndroidMxeFullPath)\$(MingwCommandPrefix32)</CMakeFlags32>
+    <CMakeFlags64>$(CMakeCommonFlags) -DCMAKE_C_COMPILER=$(AndroidMxeFullPath)\bin\$(MingwCommandPrefix64)-gcc -DCMAKE_CXX_COMPILER=$(AndroidMxeFullPath)\bin\$(MingwCommandPrefix64)-g++ -DCMAKE_RC_COMPILER=$(AndroidMxeFullPath)\bin\$(MingwCommandPrefix64)-windres -DCMAKE_FIND_ROOT_PATH=$(AndroidMxeFullPath)\$(MingwCommandPrefix64)</CMakeFlags64>
+  </PropertyGroup>
   <ItemGroup>
     <_LibZipTarget Include="host-mxe-Win64" Condition="$(AndroidSupportedHostJitAbisForConditionalChecks.Contains (':mxe-Win64:'))">
-      <CMake>$(AndroidMxeFullPath)\bin\x86_64-w64-mingw32.static-cmake</CMake>
-      <CMakeFlags></CMakeFlags>
+      <CMake>$(CMakeBinary64)</CMake>
+      <CMakeFlags>$(CMakeFlags64)</CMakeFlags>
       <OutputLibrary>x64/libzip.dll</OutputLibrary>
       <OutputLibraryPath>lib/libzip.dll</OutputLibraryPath>
     </_LibZipTarget>
     <_LibZipTarget Include="host-mxe-Win32" Condition="$(AndroidSupportedHostJitAbisForConditionalChecks.Contains (':mxe-Win32:'))">
-      <CMake>$(AndroidMxeFullPath)\bin\i686-w64-mingw32.static-cmake</CMake>
-      <CMakeFlags></CMakeFlags>
+      <CMake>$(CMakeBinary32)</CMake>
+      <CMakeFlags>$(CMakeFlags32)</CMakeFlags>
       <OutputLibrary>libzip.dll</OutputLibrary>
       <OutputLibraryPath>lib/libzip.dll</OutputLibraryPath>
     </_LibZipTarget>
diff --git a/src/libzip-windows/mingw-linux-32.cmake b/src/libzip-windows/mingw-linux-32.cmake
new file mode 100644
index 00000000000..c96f47f66e7
--- /dev/null
+++ b/src/libzip-windows/mingw-linux-32.cmake
@@ -0,0 +1,20 @@
+# the name of the target operating system
+SET(CMAKE_SYSTEM_NAME Windows)
+
+# which compilers to use for C and C++
+SET(CMAKE_C_COMPILER i686-w64-mingw32-gcc)
+SET(CMAKE_CXX_COMPILER i686-w64-mingw32-g++)
+SET(CMAKE_RC_COMPILER i686-w64-mingw32-windres)
+
+# here is the target environment located
+SET(CMAKE_FIND_ROOT_PATH /usr/i686-w64-mingw32)
+
+# adjust the default behaviour of the FIND_XXX() commands:
+# search headers and libraries in the target environment, search
+# programs in the host environment
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+
+set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
+set(BUILD_SHARED_LIBS ON)
diff --git a/src/libzip-windows/mingw-linux-64.cmake b/src/libzip-windows/mingw-linux-64.cmake
new file mode 100644
index 00000000000..11e55825ea2
--- /dev/null
+++ b/src/libzip-windows/mingw-linux-64.cmake
@@ -0,0 +1,20 @@
+# the name of the target operating system
+SET(CMAKE_SYSTEM_NAME Windows)
+
+# which compilers to use for C and C++
+SET(CMAKE_C_COMPILER x86_64-w64-mingw32-gcc)
+SET(CMAKE_CXX_COMPILER x86_64-w64-mingw32-g++)
+SET(CMAKE_RC_COMPILER x86_64-w64-mingw32-windres)
+
+# here is the target environment located
+SET(CMAKE_FIND_ROOT_PATH /usr/x86_64-w64-mingw32)
+
+# adjust the default behaviour of the FIND_XXX() commands:
+# search headers and libraries in the target environment, search
+# programs in the host environment
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+
+set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
+set(BUILD_SHARED_LIBS ON)
diff --git a/src/libzip/CMakeCacheInitialOSX.txt b/src/libzip/CMakeCacheInitialOSX.txt
new file mode 100644
index 00000000000..134f912000d
--- /dev/null
+++ b/src/libzip/CMakeCacheInitialOSX.txt
@@ -0,0 +1,13 @@
+# Force minimum macOS version to be 10.11 as this is the oldest version of the OS we support.
+# Setting this on command line won't work, for some reason, so we override the value her
+set(CMAKE_OSX_DEPLOYMENT_TARGET "10.11" CACHE STRING "Minimum OS X deployment version" FORCE)
+
+# This is necessary when cmake runs on a 10.11 system with Xcode 8.x installed in which case
+# the headers (and SDK libraries) target a later version of macOS but the host OS might not
+# have some functions found. `clonefile` is one of them - it was added in 10.12. Cmake will
+# happily "detect" clonefile even though the *host* OS doesn't have it which results in the
+# library being build but failing to load.
+#
+# Forcing a cache entry here will override the detection result, even though cmake will *still*
+# show clonefile as found in the detection output.
+set(HAVE_CLONEFILE "" CACHE INTERNAL "Force 10.11 compatibility on XA build bots" FORCE)
diff --git a/src/libzip/libzip.projitems b/src/libzip/libzip.projitems
index 7582776ebd8..94d3b82ec3a 100644
--- a/src/libzip/libzip.projitems
+++ b/src/libzip/libzip.projitems
@@ -3,13 +3,13 @@
   <ItemGroup>
     <_LibZipTarget Include="host-Darwin" Condition="$(AndroidSupportedHostJitAbisForConditionalChecks.Contains (':Darwin:'))">
       <CMake>cmake</CMake>
-      <CMakeFlags>-DCMAKE_OSX_ARCHITECTURES=&quot;i386;x86_64&quot;</CMakeFlags>
-      <OutputLibrary>libzip.3.0.dylib</OutputLibrary>
-      <OutputLibraryPath>lib/libzip.3.0.dylib</OutputLibraryPath>
+      <CMakeFlags>-C$(MSBuildThisFileDirectory)/CMakeCacheInitialOSX.txt -DCMAKE_OSX_ARCHITECTURES=&quot;i386;x86_64&quot; -DBUILD_SHARED_LIBS=ON</CMakeFlags>
+      <OutputLibrary>libzip.5.0.dylib</OutputLibrary>
+      <OutputLibraryPath>lib/libzip.5.0.dylib</OutputLibraryPath>
     </_LibZipTarget>
     <_LibZipTarget Include="host-Linux" Condition="$(AndroidSupportedHostJitAbisForConditionalChecks.Contains (':Linux:')) AND '$(_LinuxBuildLibZip)' == 'true' ">
       <CMake>cmake</CMake>
-      <CMakeFlags></CMakeFlags>
+      <CMakeFlags>-DBUILD_SHARED_LIBS=ON</CMakeFlags>
       <OutputLibrary>libzip.so</OutputLibrary>
       <OutputLibraryPath>lib/libzip.so</OutputLibraryPath>
     </_LibZipTarget>
diff --git a/src/libzip/libzip.targets b/src/libzip/libzip.targets
index 6f1dc0278bb..ee0e277345b 100644
--- a/src/libzip/libzip.targets
+++ b/src/libzip/libzip.targets
@@ -45,7 +45,7 @@
       Inputs="@(_LibZipTargetMakefile)"
       Outputs="@(Content)">
     <Exec
-        Command="make"
+        Command="make VERBOSE=1"
         WorkingDirectory="$(IntermediateOutputPath)\%(_LibZipTarget.Identity)"
      /> 
     <Copy