diff --git a/INSTALL.md b/INSTALL.md
index 5e7797b..1a9dc22 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -117,7 +117,7 @@ For Debian Trixie and Ubuntu Plucky (25.04), follow these instructions to
 download the PGP keys:
 
 ```bash
-sudo apt-get update && sudo apt-get install sq -y
+sudo apt-get update && sudo apt-get install sq ca-certificates -y
 sq network keyserver \
    --server hkps://keys.openpgp.org \
    search "DE28 AB24 1FA4 8260 FAC9 B8BA A7C9 B385 2260 4281" \