diff --git a/api/config_file_test.go b/api/config_file_test.go
new file mode 100644
index 0000000..bac20da
--- /dev/null
+++ b/api/config_file_test.go
@@ -0,0 +1,91 @@
+package main
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+func TestConfigFileLoadBasics(t *testing.T) {
+	failTestOnError(t, setupTestEnv())
+
+	f, err := ioutil.TempFile("", "commento")
+	if err != nil {
+		t.Errorf("error creating temporary file: %v", err)
+		return
+	}
+
+	defer func() {
+		if err := f.Close(); err != nil {
+			t.Errorf("error closing temporary file: %v", err)
+			return
+		}
+
+		if err := os.Remove(f.Name()); err != nil {
+			t.Errorf("error removing temporary file: %v", err)
+			return
+		}
+	}()
+
+	contents := `
+		# Commento port
+		COMMENTO_PORT=8000
+		COMMENTO_GZIP_STATIC=true
+	`
+	if _, err := f.Write([]byte(contents)); err != nil {
+		t.Errorf("error writing to temporary file: %v", err)
+		return
+	}
+
+	os.Setenv("PORT", "9000")
+	if err := configFileLoad(f.Name()); err != nil {
+		t.Errorf("unexpected error loading config file: %v", err)
+		return
+	}
+
+	if os.Getenv("PORT") != "9000" {
+		t.Errorf("expected PORT=9000 got PORT=%s", os.Getenv("PORT"))
+		return
+	}
+
+	if os.Getenv("GZIP_STATIC") != "true" {
+		t.Errorf("expected GZIP_STATIC=true got GZIP_STATIC=%s", os.Getenv("GZIP_STATIC"))
+		return
+	}
+}
+
+func TestConfigFileLoadInvalid(t *testing.T) {
+	failTestOnError(t, setupTestEnv())
+
+	f, err := ioutil.TempFile("", "commento")
+	if err != nil {
+		t.Errorf("error creating temporary file: %v", err)
+		return
+	}
+
+	defer func() {
+		if err := f.Close(); err != nil {
+			t.Errorf("error closing temporary file: %v", err)
+			return
+		}
+
+		if err := os.Remove(f.Name()); err != nil {
+			t.Errorf("error removing temporary file: %v", err)
+			return
+		}
+	}()
+
+	contents := `
+		COMMENTO_PORT=8000
+		INVALID_LINE
+	`
+	if _, err := f.Write([]byte(contents)); err != nil {
+		t.Errorf("error writing to temporary file: %v", err)
+		return
+	}
+
+	if err := configFileLoad(f.Name()); err != errorInvalidConfigFile {
+		t.Errorf("expected err=%v got err=%v", errorInvalidConfigFile, err)
+		return
+	}
+}