diff --git a/Dockerfile b/Dockerfile
index 97b987a..f176046 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 # Build the manager binary
-FROM golang:1.21 as builder
+FROM golang:1.21@sha256:4746d26432a9117a5f58e95cb9f954ddf0de128e9d5816886514199316e4a2fb as builder
 
 WORKDIR /workspace
 # Copy the Go Modules manifests
@@ -19,7 +19,7 @@ RUN CGO_ENABLED=0 GOOS=linux go build -a -o manager main.go
 
 # Use distroless as minimal base image to package the manager binary
 # Refer to https://github.com/GoogleContainerTools/distroless for more details
-FROM registry.access.redhat.com/ubi9/ubi-minimal
+FROM registry.access.redhat.com/ubi9/ubi-minimal@sha256:c7d44146f826037f6873d99da479299b889473492d3c1ab8af86f08af04ec8a0
 WORKDIR /
 COPY --from=builder /workspace/manager .
 USER 65532:65532
diff --git a/ci.Dockerfile b/ci.Dockerfile
index 724b6a1..6dea54c 100644
--- a/ci.Dockerfile
+++ b/ci.Dockerfile
@@ -1,4 +1,4 @@
-FROM registry.access.redhat.com/ubi9/ubi-minimal
+FROM registry.access.redhat.com/ubi9/ubi-minimal@sha256:c7d44146f826037f6873d99da479299b889473492d3c1ab8af86f08af04ec8a0
 WORKDIR /
 COPY bin/manager .
 USER 65532:65532