diff --git a/doc/build-unix.md b/doc/build-unix.md
index e03dc8181..9bb1a53ab 100644
--- a/doc/build-unix.md
+++ b/doc/build-unix.md
@@ -106,7 +106,7 @@ To build with Qt 4 you need the following:
 
 For Qt 5 you need the following:
 
-    sudo apt-get install libqt5gui5 libqt5core5 libqt5dbus5 qttools5-dev qttools5-dev-tools libprotobuf-dev protobuf-compiler
+    sudo apt-get install libqt5gui5 libqt5core5a libqt5dbus5 qttools5-dev qttools5-dev-tools libprotobuf-dev protobuf-compiler
 
 libqrencode (optional) can be installed with: