diff --git a/modules/caddyhttp/requestbody/requestbody_test.go b/modules/caddyhttp/requestbody/requestbody_test.go
new file mode 100644
index 000000000..40cbb4b62
--- /dev/null
+++ b/modules/caddyhttp/requestbody/requestbody_test.go
@@ -0,0 +1,134 @@
+package requestbody
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+)
+
+func TestRequestBodyCaddyModule(t *testing.T) {
+	rb := RequestBody{}
+	info := rb.CaddyModule()
+	if info.ID != "http.handlers.request_body" {
+		t.Errorf("CaddyModule().ID = %v, want 'http.handlers.request_body'", info.ID)
+	}
+	if info.New == nil {
+		t.Fatal("CaddyModule().New is nil")
+	}
+}
+
+func TestErrorWrapperMaxBytesError(t *testing.T) {
+	body := strings.NewReader("this body exceeds the limit")
+	w := httptest.NewRecorder()
+	limitedReader := http.MaxBytesReader(w, io.NopCloser(body), 5)
+	ew := errorWrapper{limitedReader}
+
+	buf := make([]byte, 100)
+	totalRead := 0
+	for {
+		n, err := ew.Read(buf[totalRead:])
+		totalRead += n
+		if err != nil {
+			httpErr, ok := err.(caddyhttp.HandlerError)
+			if !ok {
+				t.Fatalf("error should be caddyhttp.HandlerError, got %T: %v", err, err)
+			}
+			if httpErr.StatusCode != http.StatusRequestEntityTooLarge {
+				t.Errorf("status code = %d, want %d", httpErr.StatusCode, http.StatusRequestEntityTooLarge)
+			}
+			break
+		}
+	}
+}
+
+func TestErrorWrapperNormalRead(t *testing.T) {
+	body := strings.NewReader("hello")
+	w := httptest.NewRecorder()
+	limitedReader := http.MaxBytesReader(w, io.NopCloser(body), 1000)
+	ew := errorWrapper{limitedReader}
+
+	buf := make([]byte, 100)
+	n, err := ew.Read(buf)
+	if err != nil {
+		t.Fatalf("Read() error: %v", err)
+	}
+	if string(buf[:n]) != "hello" {
+		t.Errorf("Read() = %q, want %q", string(buf[:n]), "hello")
+	}
+}
+
+func TestServeHTTPMaxSize(t *testing.T) {
+	rb := RequestBody{MaxSize: 5}
+	body := io.NopCloser(strings.NewReader("this body is definitely longer than five bytes"))
+	r := httptest.NewRequest("POST", "/", body)
+	w := httptest.NewRecorder()
+
+	var calledNext bool
+	nextHandler := caddyhttp.HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
+		calledNext = true
+		data, err := io.ReadAll(r.Body)
+		if err != nil {
+			return err
+		}
+		_ = data
+		return nil
+	})
+
+	err := rb.ServeHTTP(w, r, nextHandler)
+	if !calledNext {
+		t.Error("next handler should have been called")
+	}
+	if err == nil {
+		t.Error("expected error due to MaxSize exceeded")
+	}
+}
+
+func TestServeHTTPNilBody(t *testing.T) {
+	rb := RequestBody{MaxSize: 100}
+	r := httptest.NewRequest("GET", "/", nil)
+	r.Body = nil
+	w := httptest.NewRecorder()
+
+	var calledNext bool
+	nextHandler := caddyhttp.HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
+		calledNext = true
+		return nil
+	})
+
+	err := rb.ServeHTTP(w, r, nextHandler)
+	if err != nil {
+		t.Fatalf("ServeHTTP() error: %v", err)
+	}
+	if !calledNext {
+		t.Error("next handler should have been called")
+	}
+}
+
+func TestServeHTTPZeroMaxSize(t *testing.T) {
+	rb := RequestBody{MaxSize: 0}
+	body := io.NopCloser(strings.NewReader("some body"))
+	r := httptest.NewRequest("POST", "/", body)
+	w := httptest.NewRecorder()
+
+	var bodyContent string
+	nextHandler := caddyhttp.HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
+		data, err := io.ReadAll(r.Body)
+		if err != nil {
+			return err
+		}
+		bodyContent = string(data)
+		return nil
+	})
+
+	err := rb.ServeHTTP(w, r, nextHandler)
+	if err != nil {
+		t.Fatalf("ServeHTTP() error: %v", err)
+	}
+	if bodyContent != "some body" {
+		t.Errorf("body = %q, want %q", bodyContent, "some body")
+	}
+}