diff --git a/Dockerfile b/Dockerfile
index 6f19718..1922848 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,4 +13,6 @@ FROM scratch
 COPY --from=builder /checker /checker
 USER 65534:65534
 EXPOSE 8080
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+  CMD ["/checker", "-healthcheck"]
 ENTRYPOINT ["/checker"]
diff --git a/Makefile b/Makefile
index 5a55200..a8d23d2 100644
--- a/Makefile
+++ b/Makefile
@@ -23,7 +23,7 @@ checker-carddav.so:
 	go build -buildmode=plugin -ldflags "$(GO_LDFLAGS)" -o $@ ./plugin/carddav
 
 test:
-	go test ./...
+	go test -tags standalone ./...
 
 docker: docker-caldav docker-carddav
 
diff --git a/go.mod b/go.mod
index 82ff426..6bc18b9 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module git.happydns.org/checker-dav
 go 1.25.0
 
 require (
-	git.happydns.org/checker-sdk-go v1.3.0
+	git.happydns.org/checker-sdk-go v1.5.0
 	git.happydns.org/checker-tls v0.2.0
 )
 
diff --git a/go.sum b/go.sum
index dd024c8..b40cefa 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,5 @@
-git.happydns.org/checker-sdk-go v1.3.0 h1:FG2kIhlJCzI0m35EhxSgn4UWc9M4ha6aZTeoChu4l7A=
-git.happydns.org/checker-sdk-go v1.3.0/go.mod h1:aNAcfYFfbhvH9kJhE0Njp5GX0dQbxdRB0rJ0KvSC5nI=
+git.happydns.org/checker-sdk-go v1.5.0 h1:5uD5Cm6xJ+lwnhbJ09iCXGHbYS9zRh+Yh0NeBHkAPBY=
+git.happydns.org/checker-sdk-go v1.5.0/go.mod h1:aNAcfYFfbhvH9kJhE0Njp5GX0dQbxdRB0rJ0KvSC5nI=
 git.happydns.org/checker-tls v0.2.0 h1:2dYpcePBylUc3le76fFlLbxraiLpGESmOhx4NfD7REM=
 git.happydns.org/checker-tls v0.2.0/go.mod h1:0ZSG0CTP007SHBPE7qInESVIOcW+xgucHUhHgj6MeZ8=
 github.com/emersion/go-ical v0.0.0-20240127095438-fc1c9d8fb2b6 h1:kHoSgklT8weIDl6R6xFpBJ5IioRdBU1v2X2aCZRVCcM=