diff --git a/Debugging-segfaults-and-hard-to-decipher-pybind11-bugs.md b/Debugging-segfaults-and-hard-to-decipher-pybind11-bugs.md
index 700fa46..ea49b79 100644
--- a/Debugging-segfaults-and-hard-to-decipher-pybind11-bugs.md
+++ b/Debugging-segfaults-and-hard-to-decipher-pybind11-bugs.md
@@ -70,7 +70,7 @@ The easiest way to do this is to use a debug build w/ a debug Python interpreter
 Here's an example workflow of debugging a specific unittest on CPython 3.8 on Ubuntu 18.04; this assumes the following packages are installed:
 
 ```sh
-sudo apt install cmake build-essential python3.8-dev python3.8-venv python3.8-dbg
+sudo apt install cmake build-essential ninja-build python3.8-dev python3.8-venv python3.8-dbg
 ```
 
 Then here's an example of running a unittest with GDB: