diff --git a/.buildbot.sh b/.buildbot.sh
index 21c1eb9..08b9056 100644
--- a/.buildbot.sh
+++ b/.buildbot.sh
@@ -18,7 +18,7 @@ PREFIX=test_install make install
 test -f test_install/bin/snare
 
 which cargo-deny | cargo install cargo-deny || true
-if [ "X`which cargo-deny`" != "X"]; then
+if cargo deny --version 2>&1 > /dev/null; then
     cargo-deny check license
 else
     echo "Warning: couldn't run cargo-deny" > /dev/stderr
diff --git a/deny.toml b/deny.toml
index fb55cc5..51ada7f 100644
--- a/deny.toml
+++ b/deny.toml
@@ -5,6 +5,7 @@ allow = [
     "0BSD",
     "Apache-2.0",
     "BSD-3-Clause",
+    "CC-PDDC",
     "MIT",
     "Unicode-DFS-2016",
     "Unlicense"