diff --git a/functions/http.go b/functions/http.go
index a70bf40..31cf310 100644
--- a/functions/http.go
+++ b/functions/http.go
@@ -18,19 +18,19 @@ func HttpGetPostInt(request *http.Request, key string) (value int, error error)
 	case "POST":
 		error = request.ParseForm()
 		if error != nil {
-			error = fmt.Errorf("Unable to parse HTTP POST input: %s",
+			error = fmt.Errorf("unable to parse post input: %s",
 				error.Error())
 			return
 		}
 		value, error = strconv.Atoi(request.Form.Get(key))
 		if error != nil {
 			fmt.Printf("Error parsing parameter '%s'\n", key)
-			error = fmt.Errorf("Unable to parse parameter '%s' as an integer: %s",
+			error = fmt.Errorf("unable to parse parameter '%s' as an integer: %s",
 				key, error.Error())
 		}
 		return
 	default:
-		error = fmt.Errorf("This endpoint does not support %s operations.\n", request.Method)
+		error = fmt.Errorf("this endpoint does not support %s operations", request.Method)
 		return
 	}
 }
@@ -49,7 +49,6 @@ func HttFibonacci(w http.ResponseWriter, request *http.Request) {
 		fmt.Fprintf(w, "Fibonacci sequence index [%d]: %d\n",
 			seq, MyFibonacci(seq))
 	}
-	return
 }
 
 func HttSum(w http.ResponseWriter, request *http.Request) {
diff --git a/go.mod b/go.mod
index 7e0b355..4dbb5ae 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
 module darjeeling.systemec.nl/rhouben/fibonacci
 
 go 1.24.4
+
+require github.com/joho/godotenv v1.5.1
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..d61b19e
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
diff --git a/main.go b/main.go
index 7c85383..1cb4b34 100644
--- a/main.go
+++ b/main.go
@@ -6,23 +6,37 @@ import (
 	"os"
 	"strconv"
 
+	"github.com/joho/godotenv"
+
 	"darjeeling.systemec.nl/rhouben/fibonacci/functions"
 )
 
 func main() {
-	var port_number int
+	var port_number int = 8098 // hard default
 	var error error
 	var bind_socket string
 	fmt.Println("Hello, world. I'm teaching myself Go.")
 
-	if len(os.Args) <= 1 {
-		port_number = 8088
-	} else {
-		port_number, error = strconv.Atoi(os.Args[1])
+	error = godotenv.Load() // Load .env file
+	if error != nil {
+		fmt.Printf("Error trying to load .env file: %s\n", error)
+	}
+	port_arg := os.Getenv("FIB_PORT")
+	if port_arg != "" {
+		fmt.Printf("Loaded port value '%s' from environment.\n",
+			port_arg)
+	}
+	if len(os.Args) > 1 { // commandline overrules env
+		port_arg = os.Args[1]
+		fmt.Printf("Loading port value '%s' from command line.\n",
+			port_arg)
+	}
 
+	if port_arg != "" {
+		port_number, error = strconv.Atoi(port_arg)
 		if error != nil {
-			fmt.Printf("I had an error trying to parse %s into a number: %s\n",
-				os.Args[1],
+			fmt.Printf("I had an error trying to parse '%s' into a number: %s\n",
+				port_arg,
 				error)
 			os.Exit(0)
 		}