diff --git a/.github/workflows/golangci-lint.yaml b/.github/workflows/golangci-lint.yaml
index 43de8c8..7834db4 100644
--- a/.github/workflows/golangci-lint.yaml
+++ b/.github/workflows/golangci-lint.yaml
@@ -14,7 +14,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v3
         with:
-          go-version: 1.18
+          go-version: 1.21
 
       - uses: actions/checkout@v3
 
diff --git a/Dockerfile b/Dockerfile
index 81ad522..a125c82 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:1.18.6 AS build
+FROM golang:1.21 AS build
 
 RUN mkdir -p /src
 
@@ -12,6 +12,8 @@ RUN make build-linux
 
 FROM debian:11.4-slim
 
+RUN apt update && apt install -y ca-certificates tzdata
+
 COPY --from=build /src/matrix-on-call-bot /usr/local/bin/
 
 CMD ["/usr/local/bin/matrix-on-call-bot"]
diff --git a/go.mod b/go.mod
index 08cf5da..cb00fd8 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/snapp-incubator/matrix-on-call-bot
 
-go 1.18
+go 1.21
 
 require (
 	github.com/go-playground/validator/v10 v10.11.0
diff --git a/go.sum b/go.sum
index 9387f03..6d654e3 100644
--- a/go.sum
+++ b/go.sum
@@ -838,6 +838,7 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/pquerna/cachecontrol v0.0.0-20171018203845-0dec1b30a021/go.mod h1:prYjPmNq4d1NPVmpShWobRqXY3q7Vp+80DqgxxUrUIA=
 github.com/prashantv/gostub v1.1.0 h1:BTyx3RfQjRHnUWaGF9oQos79AlQ5k8WNktv7VGvVH4g=
+github.com/prashantv/gostub v1.1.0/go.mod h1:A5zLQHz7ieHGG7is6LLXLz7I8+3LZzsrV0P1IAHhP5U=
 github.com/prometheus/client_golang v0.0.0-20180209125602-c332b6f63c06/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
 github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDft0ttaMvbicHlPoso=
@@ -942,6 +943,7 @@ github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/subosito/gotenv v1.2.0 h1:Slr1R9HxAlEKefgq5jn9U+DnETlIUa6HfgEzj0g5d7s=
 github.com/subosito/gotenv v1.2.0/go.mod h1:N0PQaV/YGNqwC0u51sEeR/aUtSLEXKX9iv69rRypqCw=
 github.com/syndtr/gocapability v0.0.0-20170704070218-db04d3cc01c8/go.mod h1:hkRG7XYTFWNJGYcbNJQlaLq0fg1yr4J4t/NcTQtrfww=