diff --git a/doc/BUILDING-external-libs.md b/doc/BUILDING-external-libs.md
index e95d6c7..ae314b4 100644
--- a/doc/BUILDING-external-libs.md
+++ b/doc/BUILDING-external-libs.md
@@ -94,7 +94,7 @@ make
 make install
 
 git clone https://github.com/zeromq/cppzmq.git
- cp cppzmq/*.hpp zeromq/include/
+cp cppzmq/*.hpp zeromq/include/
 ```
 
 ## And finally: Build Monero