diff --git a/Dockerfile b/Dockerfile
index aa8cb03..d740d7c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,4 +3,4 @@ FROM hashicorp/vault:latest
 ADD ./vault-unseal.sh /vault-unseal.sh
 RUN chmod a+x /vault-unseal.sh
 
-CMD ["/bin/sh", "while true; do /vault-unseal.sh; sleep 30; done"]
+CMD ["/bin/sh", "-c", "while true; do /vault-unseal.sh; sleep 30; done"]