diff --git a/nix/build-all.py b/nix/build-all.py
index 5033c2b2a4..a943e25f94 100644
--- a/nix/build-all.py
+++ b/nix/build-all.py
@@ -257,7 +257,7 @@ print("Building:", *sorted(targets, key=lambda t: len(list(v(t)))))
 
 # Check that required tools are in PATH
 
-for cmd in [git, bunzip2, tar, cc, cplusplus, autoconf, automake, yacc, make, "patch"]:
+for cmd in [git, bunzip2, tar, cc, cplusplus, autoconf, automake, yacc, make, "patch", "cmake"]:
     if which(cmd) is None:
         raise ValueError("Required tool '%s' not installed or not added to PATH" % (cmd,))