diff --git a/vertx-web-client/src/main/java/io/vertx/ext/web/client/impl/HttpContext.java b/vertx-web-client/src/main/java/io/vertx/ext/web/client/impl/HttpContext.java
index b26b0cca17..a747c7076c 100644
--- a/vertx-web-client/src/main/java/io/vertx/ext/web/client/impl/HttpContext.java
+++ b/vertx-web-client/src/main/java/io/vertx/ext/web/client/impl/HttpContext.java
@@ -430,15 +430,15 @@ private void handleSendRequest() {
     if (request.timeout > 0) {
       req.setTimeout(request.timeout);
     }
-    if (body != null) {
-      if (contentType != null) {
-        String prev = req.headers().get(HttpHeaders.CONTENT_TYPE);
-        if (prev == null) {
-          req.putHeader(HttpHeaders.CONTENT_TYPE, contentType);
-        } else {
-          contentType = prev;
-        }
+    if (contentType != null) {
+      String prev = req.headers().get(HttpHeaders.CONTENT_TYPE);
+      if (prev == null) {
+        req.putHeader(HttpHeaders.CONTENT_TYPE, contentType);
+      } else {
+        contentType = prev;
       }
+    }
+    if (body != null || "application/json".equals(contentType)) {
       if (body instanceof MultiMap) {
         MultipartForm parts = MultipartForm.create();
         MultiMap attributes = (MultiMap) body;
diff --git a/vertx-web-client/src/test/java/io/vertx/ext/web/client/WebClientTest.java b/vertx-web-client/src/test/java/io/vertx/ext/web/client/WebClientTest.java
index 5251f8e657..fe0d033bd2 100644
--- a/vertx-web-client/src/test/java/io/vertx/ext/web/client/WebClientTest.java
+++ b/vertx-web-client/src/test/java/io/vertx/ext/web/client/WebClientTest.java
@@ -305,6 +305,14 @@ public void testSendBufferBody() throws Exception {
     testSendBody(body, (contentType, buff) -> assertEquals(body, buff));
   }
 
+  @Test
+  public void testSendJsonNullBody() throws Exception {
+    testSendBody(null, (contentType, buff) -> {
+      assertEquals("application/json", contentType);
+//      assertEquals(body, buff.toJsonObject());
+    });
+  }
+
   private void testSendBody(Object body, BiConsumer<String, Buffer> checker) throws Exception {
     waitFor(2);
     server.requestHandler(req -> req.bodyHandler(buff -> {