diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
new file mode 100644
index 0000000..1f3d05a
--- /dev/null
+++ b/.github/workflows/test.yaml
@@ -0,0 +1,46 @@
+name: build-test
+
+on: [push]
+
+jobs:
+  test:
+    name: build-test
+    strategy:
+      fail-fast: false
+      matrix:
+        go-version: [1.17.x, 1.18.x, 1.19.x, 1.20.x, 1.21.x]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Install Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: ${{ matrix.go-version }}
+
+      - name: Build
+        run: |
+          go env -w GOFLAGS=-mod=mod
+          go build -v ./...
+
+      - name: Test With Coverage
+        run: go test -race -coverprofile=coverage -covermode=atomic
+
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v2
+        with:
+          files: ./coverage
+        if: matrix.os == 'ubuntu-latest' && matrix.go-version == '1.21.x'
+
+      - name: Go vet
+        run: |
+          go vet .
+        if: matrix.os == 'ubuntu-latest' && matrix.go-version == '1.21.x'
+
+      - name: Go Static Check
+        run: |
+          go install honnef.co/go/tools/cmd/staticcheck@latest
+          staticcheck .
+        if: matrix.os == 'ubuntu-latest' && matrix.go-version == '1.21.x'
diff --git a/filestream.go b/filestream.go
index 812df04..039d3c0 100644
--- a/filestream.go
+++ b/filestream.go
@@ -16,6 +16,7 @@ type FileStream struct {
 	info  os.FileInfo
 	f     *os.File
 	bs    *ByteStream
+	data  mmap.MMap
 }
 
 // Assert interface implementation checks
@@ -48,6 +49,7 @@ func NewFileStream(filename string) (*FileStream, error) {
 		info:  info,
 		f:     f,
 		bs:    bs,
+		data:  data,
 	}, nil
 }
 
@@ -111,5 +113,8 @@ func (fs *FileStream) IsEOF() bool {
 
 // Close underlying filestream.
 func (fs *FileStream) Close() error {
+	if fs.data != nil {
+		_ = fs.data.Unmap()
+	}
 	return fs.f.Close()
 }
diff --git a/go.mod b/go.mod
index cffa91e..ca5053a 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,6 @@ module github.com/saferwall/binstream
 go 1.15
 
 require (
-	github.com/edsrzf/mmap-go v1.0.0
-	golang.org/x/sys v0.0.0-20210319071255-635bc2c9138d // indirect
+	github.com/edsrzf/mmap-go v1.1.0
+	golang.org/x/sys v0.21.0 // indirect
 )
diff --git a/go.sum b/go.sum
index 05ae971..8ce8eb1 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,5 @@
-github.com/edsrzf/mmap-go v1.0.0 h1:CEBF7HpRnUCSJgGUb5h1Gm7e3VkmVDrR8lvWVLtrOFw=
-github.com/edsrzf/mmap-go v1.0.0/go.mod h1:YO35OhQPt3KJa3ryjFM5Bs14WD66h8eGKpfaBNrHW5M=
-golang.org/x/sys v0.0.0-20210319071255-635bc2c9138d h1:jbzgAvDZn8aEnytae+4ou0J0GwFZoHR0hOrTg4qH8GA=
-golang.org/x/sys v0.0.0-20210319071255-635bc2c9138d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+github.com/edsrzf/mmap-go v1.1.0 h1:6EUwBLQ/Mcr1EYLE4Tn1VdW1A4ckqCQWZBw8Hr0kjpQ=
+github.com/edsrzf/mmap-go v1.1.0/go.mod h1:19H/e8pUPLicwkyNgOykDXkJ9F0MHE+Z52B8EIth78Q=
+golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
+golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=