diff --git a/api/config.go b/api/config.go
index 29a3208..20db480 100644
--- a/api/config.go
+++ b/api/config.go
@@ -58,6 +58,12 @@ func configParse() error {
 		"GITLAB_SECRET": "",
 	}
 
+	if os.Getenv("COMMENTO_CONFIG_FILE") != "" {
+		if err := configFileLoad(os.Getenv("COMMENTO_CONFIG_FILE")); err != nil {
+			return err
+		}
+	}
+
 	for key, value := range defaults {
 		if os.Getenv("COMMENTO_"+key) == "" {
 			os.Setenv(key, value)
@@ -66,12 +72,6 @@ func configParse() error {
 		}
 	}
 
-	if os.Getenv("CONFIG_FILE") != "" {
-		if err := configFileLoad(os.Getenv("CONFIG_FILE")); err != nil {
-			return err
-		}
-	}
-
 	// Mandatory config parameters
 	for _, env := range []string{"POSTGRES", "PORT", "ORIGIN", "FORBID_NEW_OWNERS", "MAX_IDLE_PG_CONNECTIONS"} {
 		if os.Getenv(env) == "" {
diff --git a/api/config_file.go b/api/config_file.go
index 8303c6b..24febd2 100644
--- a/api/config_file.go
+++ b/api/config_file.go
@@ -41,11 +41,12 @@ func configFileLoad(filepath string) error {
 			continue
 		}
 
-		if os.Getenv(key[9:]) != "" {
+		if os.Getenv(key) != "" {
+			// Config files have lower precedence.
 			continue
 		}
 
-		os.Setenv(key[9:], value)
+		os.Setenv(key, value)
 	}
 
 	return nil
diff --git a/api/config_file_test.go b/api/config_file_test.go
index bac20da..4c4a56b 100644
--- a/api/config_file_test.go
+++ b/api/config_file_test.go
@@ -37,19 +37,19 @@ func TestConfigFileLoadBasics(t *testing.T) {
 		return
 	}
 
-	os.Setenv("PORT", "9000")
+	os.Setenv("COMMENTO_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"))
+	if os.Getenv("COMMENTO_PORT") != "9000" {
+		t.Errorf("expected COMMENTO_PORT=9000 got COMMENTO_PORT=%s", os.Getenv("COMMENTO_PORT"))
 		return
 	}
 
-	if os.Getenv("GZIP_STATIC") != "true" {
-		t.Errorf("expected GZIP_STATIC=true got GZIP_STATIC=%s", os.Getenv("GZIP_STATIC"))
+	if os.Getenv("COMMENTO_GZIP_STATIC") != "true" {
+		t.Errorf("expected COMMENTO_GZIP_STATIC=true got COMMENTO_GZIP_STATIC=%s", os.Getenv("COMMENTO_GZIP_STATIC"))
 		return
 	}
 }
diff --git a/api/config_test.go b/api/config_test.go
index bb11a73..df54cc3 100644
--- a/api/config_test.go
+++ b/api/config_test.go
@@ -21,6 +21,7 @@ func TestConfigParseBasics(t *testing.T) {
 
 	os.Setenv("COMMENTO_BIND_ADDRESS", "192.168.1.100")
 
+	os.Setenv("COMMENTO_PORT", "")
 	if err := configParse(); err != nil {
 		t.Errorf("unexpected error when parsing config: %v", err)
 		return