diff --git a/.changeset/happy-years-wash.md b/.changeset/happy-years-wash.md
new file mode 100644
index 0000000000000..bcd63de5cb63e
--- /dev/null
+++ b/.changeset/happy-years-wash.md
@@ -0,0 +1,5 @@
+---
+'@eth-optimism/ci-builder': patch
+---
+
+Require rebuild on null ref
diff --git a/ops/docker/ci-builder/check-changed.sh b/ops/docker/ci-builder/check-changed.sh
index 93378bd2da1c3..d0774d62eafab 100644
--- a/ops/docker/ci-builder/check-changed.sh
+++ b/ops/docker/ci-builder/check-changed.sh
@@ -33,6 +33,13 @@ else
 		exit 0
 	fi
 
+	if [ "$REF" = "null" ]; then
+		echoerr "Bad ref, requiring a total rebuild."
+		echo "TRUE"
+		exit 1
+	fi
+
+
 	echoerr "Base Ref:     $REF"
 	echoerr "Base Ref SHA: $(git show-branch --sha1-name "$REF")"
  	echoerr "Curr Ref:     $(git rev-parse --short HEAD)"