diff --git a/Makefile b/Makefile
index 93f9f0c..9113b05 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ SOURCES     = $(wildcard src/*.cpp)
 OBJECTS     = $(SOURCES:%.cpp=%.o)
 APPLICATION = arma-flow
 CXXFLAGS    = -Wall -c -O2 -std=c++17 -o
-LDFLAGS     = -larmadillo -loptions -lstdc++fs
+LDFLAGS     = -larmadillo -ljanus -lstdc++fs
 
 all:            ${OBJECTS} ${APPLICATION}
 
diff --git a/README.md b/README.md
index 033ef60..da78567 100644
--- a/README.md
+++ b/README.md
@@ -6,11 +6,25 @@ Additional support for three-phase short-circuit calculation.
 
 ## 1. Requirements
 
-* A newer version of [Armadillo](http://arma.sourceforge.net/)
+* A newer version of [Armadillo](http://arma.sourceforge.net/).
   * Tested on 8.400.0
-* The [Options](https://mulholland.xyz/docs/options/) library
-  * This library was recently renamed to Janus. In order to build correctly, you may need to modify some code.
-* Compiler with C++17 support
+* The [Janus](https://github.com/dmulholland/janus-cpp) library.
+* Compiler with C++17 support.
+
+### 1.1 Build Janus
+
+You need to build and install Janus before building arma-flow.
+
+For example:
+
+```bash
+git clone https://github.com/dmulholland/janus-cpp.git
+cd janus-cpp/src
+g++ -std=c++11 -shared -fPIC -o libjanus.so janus.cpp
+sudo cp libjanus.so /usr/lib
+sudo cp janus.h /usr/include
+```
+
 
 ## 2. Documentation
 
diff --git a/src/args.hpp b/src/args.hpp
index cf1c1b4..d9436a3 100644
--- a/src/args.hpp
+++ b/src/args.hpp
@@ -7,7 +7,7 @@
 #pragma once
 
 #include <complex>
-#include <options.h>
+#include <janus.h>
 
 namespace flow
 {
@@ -15,7 +15,7 @@ namespace flow
     class args
     {
         /// The argument parser.
-        options::ArgParser arg_parser_;
+        janus::ArgParser arg_parser_;
 
     public:
         /**