diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 27b91e2..f848935 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -7,6 +7,8 @@ jobs:
         steps:
             -   uses: actions/checkout@v2
             -   uses: actions/setup-go@v2
+            -   name: Install dependencies
+                run: sudo apt update && sudo apt install libsnmp-dev
             -   name: Build
                 run: go build ./cmd/snmp-proxy
             -   name: Upload binaries
@@ -21,8 +23,8 @@ jobs:
         steps:
             -   uses: actions/checkout@v2
             -   uses: actions/setup-go@v2
-            -   name: Install pip3
-                run: sudo apt install python3-pip
+            -   name: Install dependencies
+                run: sudo apt update && sudo apt install libsnmp-dev python3-pip snmp-mibs-downloader
             -   name: Install snmpsim
                 run: sudo pip3 install snmpsim
             -   name: Run tests
@@ -34,8 +36,8 @@ jobs:
         steps:
             -   uses: actions/checkout@v2
             -   uses: actions/setup-go@v2
-            -   name: Install pip3
-                run: sudo apt install python3-pip
+            -   name: Install dependencies
+                run: sudo apt update && sudo apt install libsnmp-dev python3-pip snmp-mibs-downloader
             -   name: Install snmpsim
                 run: sudo pip3 install snmpsim
             -   name: Download go-acc
@@ -47,12 +49,21 @@ jobs:
                 with:
                     path-to-profile: coverage.cov
 
+#    lint:
+#        name: Lint
+#        runs-on: ubuntu-latest
+#        steps:
+#            -   uses: actions/checkout@v2
+#            -   name: golangci-lint
+#                uses: golangci/golangci-lint-action@v1
+#                with:
+#                    version: v1.27
+
     lint:
         name: Lint
         runs-on: ubuntu-latest
         steps:
             -   uses: actions/checkout@v2
-            -   name: golangci-lint
-                uses: golangci/golangci-lint-action@v1
-                with:
-                    version: v1.27
+            -   uses: actions/setup-go@v2
+            -   name: Run linter
+                run: make lint || { bin/golangci-lint cache clean && bin/golangci-lint run -v ;}
diff --git a/Makefile b/Makefile
index 4dfff58..aae45ce 100644
--- a/Makefile
+++ b/Makefile
@@ -24,5 +24,9 @@ test:
 	timeout 300 go test --race ./...
 	timeout 300 go test --count 100 ./...
 
+.PHONY: clean
+clean:
+	rm -rf bin
+
 $(BIN)/golangci-lint:
 	curl --retry 5 -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s v1.27.0
diff --git a/cmd/snmp-proxy/snmp-proxy.go b/cmd/snmp-proxy/snmp-proxy.go
index 85b0c0a..89f447d 100644
--- a/cmd/snmp-proxy/snmp-proxy.go
+++ b/cmd/snmp-proxy/snmp-proxy.go
@@ -24,6 +24,7 @@ func main() {
 	}
 
 	mibParser := snmpproxy.NewNetsnmpMibParser(config.Logger, config.Snmp.StrictMibParsing)
+
 	displayHints, err := mibParser.Parse()
 	if err != nil {
 		config.Logger.Fatalw("mib parser error: ", zap.Error(err))
diff --git a/snmpproxy/mib.go b/snmpproxy/mib.go
index 89fe4a2..0a38b99 100644
--- a/snmpproxy/mib.go
+++ b/snmpproxy/mib.go
@@ -53,6 +53,7 @@ func (p *NetsnmpMibParser) Parse() (DisplayHints, error) {
 	defer w.Close()
 
 	stderrFd := int(os.Stderr.Fd())
+
 	savedStderrFd, err := syscall.Dup(stderrFd)
 	if err != nil {
 		return nil, err
@@ -88,7 +89,7 @@ func (p *NetsnmpMibParser) Parse() (DisplayHints, error) {
 	// Restore stderr
 	_ = w.Close()
 	_ = syscall.Close(stderrFd)
-	syscall.Dup2(savedStderrFd, stderrFd)
+	_ = syscall.Dup2(savedStderrFd, stderrFd)
 	_ = syscall.Close(savedStderrFd)
 
 	if err := <-errChan; err != nil {
diff --git a/snmpproxy/mib_test.go b/snmpproxy/mib_test.go
index 45992f3..ff53d56 100644
--- a/snmpproxy/mib_test.go
+++ b/snmpproxy/mib_test.go
@@ -10,11 +10,15 @@ import (
 )
 
 func TestNetsnmpMibParser_Parse(t *testing.T) {
-	mibParser := snmpproxy.NewNetsnmpMibParser(zap.NewNop().Sugar(), true)
+	require := require.New(t)
+
+	mibParser := snmpproxy.NewNetsnmpMibParser(zap.NewNop().Sugar(), false)
 	displayHints, err := mibParser.Parse()
 
-	require.NoError(t, err)
-	require.Equal(t, snmpproxy.DisplayHints{}, displayHints)
+	require.NoError(err)
+	require.NotEmpty(displayHints)
+	require.Equal(snmpproxy.DisplayHintString, displayHints[".1.3.6.1.2.1.2.2.1.2"])
+	require.Equal(snmpproxy.DisplayHintHexadecimal, displayHints[".1.3.6.1.2.1.4.22.1.2"])
 }
 
 func TestMibDataProvider_GetStringType(t *testing.T) {