diff --git a/go.mod b/go.mod
index 456b7b3e2..8170c174e 100644
--- a/go.mod
+++ b/go.mod
@@ -40,6 +40,7 @@ require (
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/fatih/structs v1.0.0 // indirect
+	github.com/gabriel-vasile/mimetype v1.4.0 // indirect
 	github.com/golang/protobuf v1.3.2 // indirect
 	github.com/jmespath/go-jmespath v0.4.0 // indirect
 	github.com/konsorten/go-windows-terminal-sequences v1.0.1 // indirect
diff --git a/go.sum b/go.sum
index 29ab9d22d..ef8eccba1 100644
--- a/go.sum
+++ b/go.sum
@@ -17,6 +17,8 @@ github.com/evalphobia/logrus_sentry v0.4.6 h1:825MLGu+SW5H8hMXGeBI7TwX7vgJLd9hz0
 github.com/evalphobia/logrus_sentry v0.4.6/go.mod h1:pKcp+vriitUqu9KiWj/VRFbRfFNUwz95/UkgG8a6MNc=
 github.com/fatih/structs v1.0.0 h1:BrX964Rv5uQ3wwS+KRUAJCBBw5PQmgJfJ6v4yly5QwU=
 github.com/fatih/structs v1.0.0/go.mod h1:9NiDSp5zOcgEDl+j00MP/WkGVPOlPRLejGD8Ga6PJ7M=
+github.com/gabriel-vasile/mimetype v1.4.0 h1:Cn9dkdYsMIu56tGho+fqzh7XmvY2YyGU0FnbhiOsEro=
+github.com/gabriel-vasile/mimetype v1.4.0/go.mod h1:fA8fi6KUiG7MgQQ+mEWotXoEOvmxRtOJlERCzSmRvr8=
 github.com/getsentry/raven-go v0.0.0-20180517221441-ed7bcb39ff10 h1:YO10pIIBftO/kkTFdWhctH96grJ7qiy7bMdiZcIvPKs=
 github.com/getsentry/raven-go v0.0.0-20180517221441-ed7bcb39ff10/go.mod h1:KungGk8q33+aIAZUIVWZDr2OfAEBsO49PX4NzFV5kcQ=
 github.com/go-chi/chi v4.1.2+incompatible h1:fGFk2Gmi/YKXk0OmGfBh0WgmN3XB8lVnEyNz34tQRec=
@@ -114,6 +116,7 @@ golang.org/x/mod v0.4.2 h1:Gz96sIWK3OalVv/I/qNygP42zyoKp3xptRVCWRFEBvo=
 golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20210505024714-0287a6fb4125/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20210614182718-04defd469f4e h1:XpT3nA5TvE525Ne3hInMh6+GETgn27Zfm9dxsThnX2Q=
 golang.org/x/net v0.0.0-20210614182718-04defd469f4e/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
diff --git a/handlers/whatsapp/whatsapp.go b/handlers/whatsapp/whatsapp.go
index e1e58af95..29675733f 100644
--- a/handlers/whatsapp/whatsapp.go
+++ b/handlers/whatsapp/whatsapp.go
@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/buger/jsonparser"
+	"github.com/gabriel-vasile/mimetype"
 	"github.com/nyaruka/courier"
 	"github.com/nyaruka/courier/backends/rapidpro"
 	"github.com/nyaruka/courier/handlers"
@@ -403,10 +404,10 @@ var waIgnoreStatuses = map[string]bool{
 // }
 
 type mtTextPayload struct {
-	To   string `json:"to"    validate:"required"`
-	Type string `json:"type"  validate:"required"`
-	PreviewURL bool `json:"preview_url,omitempty"`
-	Text struct {
+	To         string `json:"to"    validate:"required"`
+	Type       string `json:"type"  validate:"required"`
+	PreviewURL bool   `json:"preview_url,omitempty"`
+	Text       struct {
 		Body string `json:"body" validate:"required"`
 	} `json:"text"`
 }
@@ -795,14 +796,14 @@ func buildPayloads(msg courier.Msg, h *handler) ([]interface{}, []*courier.Chann
 					var payload mtTextPayload
 					if strings.Contains(part, "https://") || strings.Contains(part, "http://") {
 						payload = mtTextPayload{
-							To:          msg.URN().Path(),
-							Type:        "text",
+							To:         msg.URN().Path(),
+							Type:       "text",
 							PreviewURL: true,
 						}
 					} else {
 						payload = mtTextPayload{
-							To:          msg.URN().Path(),
-							Type:        "text",
+							To:   msg.URN().Path(),
+							Type: "text",
 						}
 					}
 					payload.Text.Body = part
@@ -934,7 +935,14 @@ func (h *handler) fetchMediaID(msg courier.Msg, mimeType, mediaURL string) (stri
 		return "", logs, errors.Wrapf(err, "error building request to media endpoint")
 	}
 	setWhatsAppAuthHeader(&req.Header, msg.Channel())
-	req.Header.Add("Content-Type", http.DetectContentType(rr.Body))
+	mtype := http.DetectContentType(rr.Body)
+
+	if mtype != mimeType || mtype == "application/octet-stream" || mtype == "application/zip" {
+		mimeT := mimetype.Detect(rr.Body)
+		req.Header.Add("Content-Type", mimeT.String())
+	} else {
+		req.Header.Add("Content-Type", mtype)
+	}
 	rr, err = utils.MakeHTTPRequest(req)
 	log = courier.NewChannelLogFromRR("Uploading media to WhatsApp", msg.Channel(), msg.ID(), rr).WithError("Error uploading media to WhatsApp", err)
 	logs = append(logs, log)