diff --git a/CMakeLists.txt b/CMakeLists.txt
index 54f8768..e53151b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.10)
 
 #
 # Here we check whether mio is being configured in isolation or as a component
diff --git a/include/mio/detail/mmap.ipp b/include/mio/detail/mmap.ipp
index 716a171..19cbb93 100644
--- a/include/mio/detail/mmap.ipp
+++ b/include/mio/detail/mmap.ipp
@@ -21,11 +21,12 @@
 #ifndef MIO_BASIC_MMAP_IMPL
 #define MIO_BASIC_MMAP_IMPL
 
-#include "mio/mmap.hpp"
 #include "mio/page.hpp"
 #include "mio/detail/string_util.hpp"
 
 #include <algorithm>
+#include <cstddef>
+#include <cstdint>
 
 #ifndef _WIN32
 # include <unistd.h>
@@ -43,13 +44,13 @@ namespace win {
 /** Returns the 4 upper bytes of an 8-byte integer. */
 inline DWORD int64_high(int64_t n) noexcept
 {
-    return n >> 32;
+    return static_cast<DWORD>(n >> 32);
 }
 
 /** Returns the 4 lower bytes of an 8-byte integer. */
 inline DWORD int64_low(int64_t n) noexcept
 {
-    return n & 0xffffffff;
+    return static_cast<DWORD>(n & 0xffffffff);
 }
 
 inline std::wstring s_2_ws(const std::string& s)
@@ -60,7 +61,7 @@ inline std::wstring s_2_ws(const std::string& s)
         ret.resize(s.size());
         int wide_char_count = MultiByteToWideChar(CP_UTF8, 0, s.c_str(),
             static_cast<int>(s.size()), &ret[0], static_cast<int>(s.size()));
-        ret.resize(wide_char_count);
+        ret.resize(static_cast<std::size_t>(wide_char_count));
     }
     return ret;
 }
@@ -107,7 +108,7 @@ inline std::error_code last_error() noexcept
 {
     std::error_code error;
 #ifdef _WIN32
-    error.assign(GetLastError(), std::system_category());
+    error.assign(static_cast<int>(GetLastError()), std::system_category());
 #else
     error.assign(errno, std::system_category());
 #endif
@@ -147,7 +148,7 @@ inline size_t query_file_size(file_handle_type handle, std::error_code& error)
         error = detail::last_error();
         return 0;
     }
-	return static_cast<int64_t>(file_size.QuadPart);
+	return static_cast<size_t>(file_size.QuadPart);
 #else // POSIX
     struct stat sbuf;
     if(::fstat(handle, &sbuf) == -1)
@@ -155,7 +156,7 @@ inline size_t query_file_size(file_handle_type handle, std::error_code& error)
         error = detail::last_error();
         return 0;
     }
-    return sbuf.st_size;
+    return static_cast<size_t>(sbuf.st_size);
 #endif
 }
 
@@ -172,7 +173,7 @@ struct mmap_context
 inline mmap_context memory_map(const file_handle_type file_handle, const int64_t offset,
     const int64_t length, const access_mode mode, std::error_code& error)
 {
-    const int64_t aligned_offset = make_offset_page_aligned(offset);
+  const int64_t aligned_offset = static_cast<int64_t>(make_offset_page_aligned(static_cast<size_t>(offset)));
     const int64_t length_to_map = offset - aligned_offset + length;
 #ifdef _WIN32
     const int64_t max_file_size = offset + length;
@@ -193,7 +194,7 @@ inline mmap_context memory_map(const file_handle_type file_handle, const int64_t
             mode == access_mode::read ? FILE_MAP_READ : FILE_MAP_WRITE,
             win::int64_high(aligned_offset),
             win::int64_low(aligned_offset),
-            length_to_map));
+            static_cast<size_t>(length_to_map)));
     if(mapping_start == nullptr)
     {
         // Close file handle if mapping it failed.
@@ -204,8 +205,8 @@ inline mmap_context memory_map(const file_handle_type file_handle, const int64_t
 #else // POSIX
     char* mapping_start = static_cast<char*>(::mmap(
             0, // Don't give hint as to where to map.
-            length_to_map,
-            mode == access_mode::read ? PROT_READ : PROT_WRITE,
+            static_cast<size_t>(length_to_map),
+            mode == access_mode::read ? PROT_READ : PROT_READ | PROT_WRITE,
             MAP_SHARED,
             file_handle,
             aligned_offset));
@@ -345,8 +346,8 @@ void basic_mmap<AccessMode, ByteT>::map(const handle_type handle,
         return;
     }
 
-    const auto ctx = detail::memory_map(handle, offset,
-            length == map_entire_file ? (file_size - offset) : length,
+    const auto ctx = detail::memory_map(handle, static_cast<int64_t>(offset),
+            static_cast<int64_t>(length == map_entire_file ? (file_size - offset) : length),
             AccessMode, error);
     if(!error)
     {
@@ -359,8 +360,8 @@ void basic_mmap<AccessMode, ByteT>::map(const handle_type handle,
         file_handle_ = handle;
         is_handle_internal_ = false;
         data_ = reinterpret_cast<pointer>(ctx.data);
-        length_ = ctx.length;
-        mapped_length_ = ctx.mapped_length;
+        length_ = static_cast<size_t>(ctx.length);
+        mapped_length_ = static_cast<size_t>(ctx.mapped_length);
 #ifdef _WIN32
         file_mapping_handle_ = ctx.file_mapping_handle;
 #endif
diff --git a/include/mio/page.hpp b/include/mio/page.hpp
index cae7377..4868128 100644
--- a/include/mio/page.hpp
+++ b/include/mio/page.hpp
@@ -21,6 +21,7 @@
 #ifndef MIO_PAGE_HEADER
 #define MIO_PAGE_HEADER
 
+#include <cstddef>
 #ifdef _WIN32
 # include <windows.h>
 #else
@@ -48,7 +49,7 @@ enum class access_mode
  */
 inline size_t page_size()
 {
-    static const size_t page_size = []
+  static const size_t page_size = static_cast<size_t>([]
     {
 #ifdef _WIN32
         SYSTEM_INFO SystemInfo;
@@ -57,7 +58,7 @@ inline size_t page_size()
 #else
         return sysconf(_SC_PAGE_SIZE);
 #endif
-    }();
+    }());
     return page_size;
 }