diff --git a/Makefile b/Makefile
index 610b789..df86b27 100644
--- a/Makefile
+++ b/Makefile
@@ -1,20 +1,11 @@
-CC=gcc
 CFLAGS=-Wall -Werror -pthread -O3 -g0
+CFLAGS += -DGETRANDOM -DARG_REPLACE_GETOPT=0
 LDFLAGS=-lm -s
 
 default: inexact
 
-windows: CC=x86_64-w64-mingw32-gcc
-windows: CFLAGS=-Wall -Werror -pthread -O3 -g0
-windows: LDFLAGS=-lm -s
-windows: inexact
-
-windows-debug: CC=x86_64-w64-mingw32-gcc
-windows-debug: CFLAGS=-Wall -Werror -pthread -O3 -g
-windows-debug: LDFLAGS=-lm
-windows-debug: inexact
-
-debug: CFLAGS=-Wall -Werror -pthread -O3 -g
+debug: CFLAGS=-Wall -Werror -pthread -O0 -g
+debug: CFLAGS += -DGETRANDOM -DARG_REPLACE_GETOPT=0
 debug: LDFLAGS=-lm
 debug: inexact
 
diff --git a/README.md b/README.md
index c657f49..7e12876 100644
--- a/README.md
+++ b/README.md
@@ -62,20 +62,13 @@ Schematic:
 
 ## How to build
 
-For GNU/Linux and Mac OS X:
+For GNU/Linux and macOS, you must have GCC or Clang installed. For Windows, w64-mingw32-gcc is required.
 
 ```
   cd inexact
   make
 ```
 
-For Microsoft Windows using cross compilation on GNU/Linux:
-
-```
-  cd inexact
-  make windows
-```
-
 ## Usage
 
 Asymmetric encryption:
@@ -139,4 +132,3 @@ Inexact is released under CC0 licence, except for this externals libraries:
 - https://nachtimwald.com/2017/09/24/hex-encode-and-decode-in-c/
 - https://github.com/argtable/argtable3
 - https://github.com/dsprenkels/randombytes
-