diff --git a/cmd/build_test.go b/cmd/build_test.go
index b0d8e70c..6e862875 100644
--- a/cmd/build_test.go
+++ b/cmd/build_test.go
@@ -88,3 +88,32 @@ func TestBuildBinaryName(t *testing.T) {
 	cnt = strings.Count(string(out), "GoCover")
 	assert.Equal(t, cnt > 0, true, "GoCover varibale should be in the binary")
 }
+
+// test if goc can get variables in internal package
+func TestBuildBinaryForInternalPackage(t *testing.T) {
+	startTime := time.Now()
+
+	workingDir := filepath.Join(baseDir, "../tests/samples/simple_project_with_internal")
+	gopath := ""
+
+	os.Setenv("GOPATH", gopath)
+	os.Setenv("GO111MODULE", "on")
+
+	buildFlags, buildOutput = "", ""
+	args := []string{"."}
+	runBuild(args, workingDir)
+
+	obj := filepath.Join(workingDir, "simple-project")
+	fInfo, err := os.Lstat(obj)
+	assert.Equal(t, err, nil, "the binary should be generated.")
+	assert.Equal(t, startTime.Before(fInfo.ModTime()), true, obj+"new binary should be generated, not the old one")
+
+	cmd := exec.Command("go", "tool", "objdump", "simple-project")
+	cmd.Dir = workingDir
+	out, _ := cmd.CombinedOutput()
+	cnt := strings.Count(string(out), "GoCacheCover")
+	assert.Equal(t, cnt > 0, true, "GoCacheCover variable for internal package should be in the binary")
+
+	cnt = strings.Count(string(out), "internal.GoCover")
+	assert.Equal(t, cnt > 0, true, "internal.GoCover varibale should be in the binary")
+}
diff --git a/pkg/cover/cover_test.go b/pkg/cover/cover_test.go
index 7bf15499..f1a0de4c 100644
--- a/pkg/cover/cover_test.go
+++ b/pkg/cover/cover_test.go
@@ -18,6 +18,7 @@ package cover
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -342,3 +343,30 @@ func TestListPackagesForSimpleModProject(t *testing.T) {
 	}
 
 }
+
+// test if goc can get variables in internal package
+func TestCoverResultForInternalPackage(t *testing.T) {
+
+	workingDir := "../../tests/samples/simple_project_with_internal"
+	gopath := ""
+
+	os.Setenv("GOPATH", gopath)
+	os.Setenv("GO111MODULE", "on")
+
+	testDir := filepath.Join(os.TempDir(), "goc-build-test")
+	copy.Copy(workingDir, testDir)
+
+	Execute("", gopath, testDir, "count", "", "http://127.0.0.1:7777")
+
+	_, err := os.Lstat(filepath.Join(testDir, "http_cover_apis_auto_generated.go"))
+	if !assert.Equal(t, err, nil) {
+		assert.FailNow(t, "should generate http_cover_apis_auto_generated.go")
+	}
+
+	out, err := ioutil.ReadFile(filepath.Join(testDir, "http_cover_apis_auto_generated.go"))
+	cnt := strings.Count(string(out), "GoCacheCover")
+	assert.Equal(t, cnt > 0, true, "GoCacheCover variable should be in http_cover_apis_auto_generated.go")
+
+	cnt = strings.Count(string(out), "example.com/simple-project/internal/foo.go")
+	assert.Equal(t, cnt > 0, true, "`example.com/simple-project/internal/foo.go` should be in http_cover_apis_auto_generated.go")
+}
diff --git a/tests/samples/simple_project_with_internal/go.mod b/tests/samples/simple_project_with_internal/go.mod
new file mode 100644
index 00000000..610643a1
--- /dev/null
+++ b/tests/samples/simple_project_with_internal/go.mod
@@ -0,0 +1,3 @@
+module example.com/simple-project
+
+go 1.11
diff --git a/tests/samples/simple_project_with_internal/internal/foo.go b/tests/samples/simple_project_with_internal/internal/foo.go
new file mode 100644
index 00000000..90912fca
--- /dev/null
+++ b/tests/samples/simple_project_with_internal/internal/foo.go
@@ -0,0 +1,7 @@
+package internal
+
+import "fmt"
+
+func Hello() {
+	fmt.Println("hello, world.")
+}
diff --git a/tests/samples/simple_project_with_internal/main.go b/tests/samples/simple_project_with_internal/main.go
new file mode 100644
index 00000000..5bd41fa2
--- /dev/null
+++ b/tests/samples/simple_project_with_internal/main.go
@@ -0,0 +1,7 @@
+package main
+
+import "example.com/simple-project/internal"
+
+func main() {
+	internal.Hello()
+}