diff --git a/Build.md b/Build.md
index 2c19f82..a6ba7de 100644
--- a/Build.md
+++ b/Build.md
@@ -12,7 +12,7 @@ make
 ```
 sudo add-apt-repository ppa:jonathonf/gcc-7.1
 sudo apt-get update
-apt-get install gcc-7 g++-7
+sudo apt-get install gcc-7 g++-7
 ```
 When run cmake manually specify C and C++ compiler:
 ```