diff --git a/CMakeLists.txt b/CMakeLists.txt
index 623b09c..75581aa 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,7 +7,16 @@
 cmake_minimum_required(VERSION 3.2)
 project(maconv)
 
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra")
+add_compile_options(-Wall)
+add_compile_options(-Wextra)
+
+# Register keyword is gone in C++17 and above.  Okay
+# if we use c++std 14 and just ignore the warning.
+add_compile_options(-Wno-deprecated-register)
+
+set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
 
 # Compile vendor libraries.
 add_subdirectory("vendors/libhfs")
diff --git a/src/utils/buffer_stream.cc b/src/utils/buffer_stream.cc
index 416b03d..ba5a449 100644
--- a/src/utils/buffer_stream.cc
+++ b/src/utils/buffer_stream.cc
@@ -71,7 +71,7 @@ auto RawDataStreamBuf::seekpos(pos_type pos, std::ios_base::openmode which)
     if (which & std::ios_base::in)
         setg(eback(), eback() + pos, egptr());
     if (which & std::ios_base::out)
-        pbump(pos - (pptr() - eback()));
+        pbump(pos - static_cast<pos_type>((pptr() - eback())));
 
     return pos;
 }