diff --git a/Dockerfile b/Dockerfile
index fdc61df..19cf15b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 # Build the manager binary
-FROM golang:1.16 as builder
+FROM golang:1.16@sha256:5f6a4662de3efc6d6bb812d02e9de3d8698eea16b8eb7281f03e6f3e8383018e 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/ubi8/ubi-minimal
+FROM registry.access.redhat.com/ubi8/ubi-minimal@sha256:288239021a429a311233d73a7d91b0a1dd889ab7bbc247d913e1b5726e25354a
 WORKDIR /
 COPY --from=builder /workspace/manager .
 COPY config/templates /templates
diff --git a/ci.Dockerfile b/ci.Dockerfile
index 7d9dfd0..1168806 100644
--- a/ci.Dockerfile
+++ b/ci.Dockerfile
@@ -1,4 +1,4 @@
-FROM registry.access.redhat.com/ubi8/ubi-minimal
+FROM registry.access.redhat.com/ubi8/ubi-minimal@sha256:288239021a429a311233d73a7d91b0a1dd889ab7bbc247d913e1b5726e25354a
 WORKDIR /
 COPY config/templates /templates
 COPY bin/manager .
diff --git a/config/manager/kustomization.yaml b/config/manager/kustomization.yaml
index 396c886..2259145 100644
--- a/config/manager/kustomization.yaml
+++ b/config/manager/kustomization.yaml
@@ -13,4 +13,4 @@ kind: Kustomization
 images:
 - name: controller
   newName: quay.io/raffaelespazzoli/proactive-node-scaling-operator
-  newTag: latest
+  newTag: latest@sha256:2596964c2c4c88b4120ace715702f3505cfdaf46f064acb56f6f649dbc0480ad