diff --git a/cmd/bucket-handlers.go b/cmd/bucket-handlers.go
index 08b977481..4dba722f2 100644
--- a/cmd/bucket-handlers.go
+++ b/cmd/bucket-handlers.go
@@ -1018,6 +1018,20 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 		writeErrorResponse(ctx, w, apiErr, r.URL)
 		return
 	}
+	checksum, err := hash.GetContentChecksum(formValues)
+	if err != nil {
+		apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
+		apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, fmt.Errorf("Invalid checksum: %w", err))
+		writeErrorResponse(ctx, w, apiErr, r.URL)
+		return
+	}
+	if checksum != nil && checksum.Type.Trailing() {
+		// Not officially supported in POST requests.
+		apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
+		apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, errors.New("Trailing checksums not available for POST operations"))
+		writeErrorResponse(ctx, w, apiErr, r.URL)
+		return
+	}
 
 	formValues.Set("Bucket", bucket)
 	if fileName != "" && strings.Contains(formValues.Get("Key"), "${filename}") {
@@ -1073,6 +1087,13 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
 		return
 	}
+	if checksum != nil && checksum.Valid() {
+		err = hashReader.AddChecksum(r, false)
+		if err != nil {
+			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
+			return
+		}
+	}
 
 	// Handle policy if it is set.
 	if len(policyBytes) > 0 {
@@ -1167,6 +1188,13 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
 			return
 		}
+		if checksum != nil && checksum.Valid() {
+			err = hashReader.AddChecksum(r, true)
+			if err != nil {
+				writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
+				return
+			}
+		}
 		pReader, err = pReader.WithEncryption(hashReader, &objectEncryptionKey)
 		if err != nil {
 			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
@@ -1226,6 +1254,11 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 		return
 	}
 
+	// Add checksum header.
+	if checksum != nil && checksum.Valid() {
+		hash.AddChecksumHeader(w, checksum.AsMap())
+	}
+
 	// Decide what http response to send depending on success_action_status parameter
 	switch successStatus {
 	case "201":
diff --git a/cmd/object-api-options.go b/cmd/object-api-options.go
index a89a753b2..909713cf5 100644
--- a/cmd/object-api-options.go
+++ b/cmd/object-api-options.go
@@ -291,7 +291,7 @@ func putOpts(ctx context.Context, r *http.Request, bucket, object string, metada
 		metadata = make(map[string]string)
 	}
 
-	wantCRC, err := hash.GetContentChecksum(r)
+	wantCRC, err := hash.GetContentChecksum(r.Header)
 	if err != nil {
 		return opts, InvalidArgument{
 			Bucket: bucket,
@@ -377,7 +377,7 @@ func completeMultipartOpts(ctx context.Context, r *http.Request, bucket, object
 			}
 		}
 	}
-	opts.WantChecksum, err = hash.GetContentChecksum(r)
+	opts.WantChecksum, err = hash.GetContentChecksum(r.Header)
 	if err != nil {
 		return opts, InvalidArgument{
 			Bucket: bucket,
diff --git a/internal/hash/checksum.go b/internal/hash/checksum.go
index 86b4b78d0..10f596e6b 100644
--- a/internal/hash/checksum.go
+++ b/internal/hash/checksum.go
@@ -341,7 +341,7 @@ func (c *Checksum) AsMap() map[string]string {
 // TransferChecksumHeader will transfer any checksum value that has been checked.
 // If checksum was trailing, they must have been added to r.Trailer.
 func TransferChecksumHeader(w http.ResponseWriter, r *http.Request) {
-	c, err := GetContentChecksum(r)
+	c, err := GetContentChecksum(r.Header)
 	if err != nil || c == nil {
 		return
 	}
@@ -375,8 +375,8 @@ func AddChecksumHeader(w http.ResponseWriter, c map[string]string) {
 // GetContentChecksum returns content checksum.
 // Returns ErrInvalidChecksum if so.
 // Returns nil, nil if no checksum.
-func GetContentChecksum(r *http.Request) (*Checksum, error) {
-	if trailing := r.Header.Values(xhttp.AmzTrailer); len(trailing) > 0 {
+func GetContentChecksum(h http.Header) (*Checksum, error) {
+	if trailing := h.Values(xhttp.AmzTrailer); len(trailing) > 0 {
 		var res *Checksum
 		for _, header := range trailing {
 			var duplicates bool
@@ -402,7 +402,7 @@ func GetContentChecksum(r *http.Request) (*Checksum, error) {
 			return res, nil
 		}
 	}
-	t, s := getContentChecksum(r)
+	t, s := getContentChecksum(h)
 	if t == ChecksumNone {
 		if s == "" {
 			return nil, nil
@@ -418,21 +418,21 @@ func GetContentChecksum(r *http.Request) (*Checksum, error) {
 
 // getContentChecksum returns content checksum type and value.
 // Returns ChecksumInvalid if so.
-func getContentChecksum(r *http.Request) (t ChecksumType, s string) {
+func getContentChecksum(h http.Header) (t ChecksumType, s string) {
 	t = ChecksumNone
-	alg := r.Header.Get(xhttp.AmzChecksumAlgo)
+	alg := h.Get(xhttp.AmzChecksumAlgo)
 	if alg != "" {
 		t |= NewChecksumType(alg)
 		if t.IsSet() {
 			hdr := t.Key()
-			if s = r.Header.Get(hdr); s == "" {
+			if s = h.Get(hdr); s == "" {
 				return ChecksumNone, ""
 			}
 		}
 		return t, s
 	}
 	checkType := func(c ChecksumType) {
-		if got := r.Header.Get(c.Key()); got != "" {
+		if got := h.Get(c.Key()); got != "" {
 			// If already set, invalid
 			if t != ChecksumNone {
 				t = ChecksumInvalid
diff --git a/internal/hash/reader.go b/internal/hash/reader.go
index b4c987ee9..1dff95a62 100644
--- a/internal/hash/reader.go
+++ b/internal/hash/reader.go
@@ -170,7 +170,7 @@ func (r *Reader) SetExpectedMax(expectedMax int64) {
 // https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html
 // Returns ErrInvalidChecksum if a problem with the checksum is found.
 func (r *Reader) AddChecksum(req *http.Request, ignoreValue bool) error {
-	cs, err := GetContentChecksum(req)
+	cs, err := GetContentChecksum(req.Header)
 	if err != nil {
 		return ErrInvalidChecksum
 	}
@@ -181,6 +181,16 @@ func (r *Reader) AddChecksum(req *http.Request, ignoreValue bool) error {
 	if cs.Type.Trailing() {
 		r.trailer = req.Trailer
 	}
+	return r.AddNonTrailingChecksum(cs, ignoreValue)
+}
+
+// AddNonTrailingChecksum will add a checksum to the reader.
+// The checksum cannot be trailing.
+func (r *Reader) AddNonTrailingChecksum(cs *Checksum, ignoreValue bool) error {
+	if cs == nil {
+		return nil
+	}
+	r.contentHash = *cs
 	if ignoreValue {
 		// Do not validate, but allow for transfer
 		return nil