diff --git a/serial.cmake b/serial.cmake
index f705af5..ade12bd 100644
--- a/serial.cmake
+++ b/serial.cmake
@@ -10,6 +10,18 @@ macro(build_serial)
   project(Serial)
 
   ## Configurations
+  # Enable warnings
+  # Assuming unix means a gcc style compiler, eg. g++ or clang++.
+  IF(UNIX)
+    set(CMAKE_CXX_FLAGS "-ferror-limit=5 -Wall -Weffc++ -pedantic -pedantic-errors -Wextra  -Wall -Waggregate-return -Wcast-align -Wcast-qual  -Wchar-subscripts  -Wcomment -Wconversion -Wdisabled-optimization -Wfloat-equal  -Wformat  -Wformat=2 -Wformat-nonliteral -Wformat-security  -Wformat-y2k -Wimplicit  -Wimport  -Winit-self  -Winline -Winvalid-pch   -Wlong-long -Wmissing-braces -Wmissing-field-initializers -Wmissing-format-attribute   -Wmissing-include-dirs -Wmissing-noreturn -Wpacked -Wparentheses  -Wpointer-arith -Wredundant-decls -Wreturn-type -Wsequence-point  -Wshadow -Wsign-compare  -Wstack-protector -Wstrict-aliasing -Wstrict-aliasing=2 -Wswitch  -Wswitch-default -Wswitch-enum -Wtrigraphs  -Wuninitialized -Wunknown-pragmas  -Wunreachable-code -Wunused -Wunused-function  -Wunused-label  -Wunused-parameter -Wunused-value  -Wunused-variable  -Wvariadic-macros -Wvolatile-register-var  -Wwrite-strings")
+  ELSEIF(WIN32)
+    # Force to always compile with W4
+    if(CMAKE_CXX_FLAGS MATCHES "/W[0-4]")
+      string(REGEX REPLACE "/W[0-4]" "/W4" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+    else()
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4")
+    endif()
+  endif(UNIX)
 
   # Use clang if available
   IF(EXISTS /usr/bin/clang)
@@ -17,7 +29,6 @@ macro(build_serial)
     set(CMAKE_OSX_DEPLOYMENT_TARGET "")
     set(SERIAL_BUILD_WARNINGS TRUE)
     IF(SERIAL_BUILD_WARNINGS)
-      set(CMAKE_CXX_FLAGS "-ferror-limit=5 -Wall -Weffc++ -pedantic -pedantic-errors -Wextra  -Wall -Waggregate-return -Wcast-align -Wcast-qual  -Wchar-subscripts  -Wcomment -Wconversion -Wdisabled-optimization -Wfloat-equal  -Wformat  -Wformat=2 -Wformat-nonliteral -Wformat-security  -Wformat-y2k -Wimplicit  -Wimport  -Winit-self  -Winline -Winvalid-pch   -Wlong-long -Wmissing-braces -Wmissing-field-initializers -Wmissing-format-attribute   -Wmissing-include-dirs -Wmissing-noreturn -Wpacked -Wparentheses  -Wpointer-arith -Wredundant-decls -Wreturn-type -Wsequence-point  -Wshadow -Wsign-compare  -Wstack-protector -Wstrict-aliasing -Wstrict-aliasing=2 -Wswitch  -Wswitch-default -Wswitch-enum -Wtrigraphs  -Wuninitialized -Wunknown-pragmas  -Wunreachable-code -Wunused -Wunused-function  -Wunused-label  -Wunused-parameter -Wunused-value  -Wunused-variable  -Wvariadic-macros -Wvolatile-register-var  -Wwrite-strings")
     ELSE(SERIAL_BUILD_WARNINGS)
       set(CMAKE_CXX_FLAGS "-ferror-limit=5")
     ENDIF(SERIAL_BUILD_WARNINGS)