diff --git a/CMakeLists.txt b/CMakeLists.txt
index 45061546f..2a5d54e2e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -738,8 +738,8 @@ if(NOT ARMADILLO_FOUND)
      message (STATUS " Armadillo will be downloaded and built automatically ")
      message (STATUS " when doing 'make'. ")
 
-     set(armadillo_RELEASE 4.600.2)
-     set(armadillo_MD5 "cfa4962bfa48bf3953d012b2f8fcfa35")
+     set(armadillo_RELEASE 4.650.4)
+     set(armadillo_MD5 "e575dc01cf60e290a467c7c6d3171ef3")
 
      ExternalProject_Add(
          armadillo-${armadillo_RELEASE}
diff --git a/README.md b/README.md
index e8f43bf1f..ca3488a2f 100644
--- a/README.md
+++ b/README.md
@@ -95,9 +95,9 @@ $ sudo apt-get install libopenblas-dev liblapack-dev gfortran   # For Debian/Ubu
 $ sudo yum install lapack-devel blas-devel gcc-fortran          # For Fedora/CentOS/RHEL
 $ sudo zypper install lapack-devel blas-devel gcc-fortran       # For OpenSUSE
 
-$ wget http://sourceforge.net/projects/arma/files/armadillo-4.600.2.tar.gz
-$ tar xvfz armadillo-4.600.2.tar.gz
-$ cd armadillo-4.600.2
+$ wget http://sourceforge.net/projects/arma/files/armadillo-4.650.4.tar.gz
+$ tar xvfz armadillo-4.650.4.tar.gz
+$ cd armadillo-4.650.4
 $ cmake .
 $ make
 $ sudo make install