diff --git a/route/v1/storage.go b/route/v1/storage.go
index bdc3294..5946207 100644
--- a/route/v1/storage.go
+++ b/route/v1/storage.go
@@ -98,14 +98,19 @@ func GetStorageList(ctx echo.Context) error {
 }
 
 func PostAddStorage(ctx echo.Context) error {
-	js := make(map[string]interface{})
-	if err := ctx.Bind(&js); err != nil {
+	// Typed rather than a map: a field of the wrong type is Bind's 400, where the
+	// map's type assertions panicked, and a missing one is its zero value -- an
+	// empty path is refused below, before any disk is touched.
+	var request struct {
+		Path   string `json:"path"`
+		Name   string `json:"name"`
+		Format bool   `json:"format"`
+	}
+	if err := ctx.Bind(&request); err != nil {
 		return ctx.JSON(http.StatusBadRequest, model.Result{Success: common_err.INVALID_PARAMS, Message: common_err.GetMsg(common_err.INVALID_PARAMS), Data: err.Error()})
 	}
 
-	path := js["path"].(string)
-	name := js["name"].(string)
-	format := js["format"].(bool)
+	path, name, format := request.Path, request.Name, request.Format
 
 	if len(path) == 0 {
 		return ctx.JSON(common_err.CLIENT_ERROR, model.Result{Success: common_err.INVALID_PARAMS, Message: common_err.GetMsg(common_err.INVALID_PARAMS)})
diff --git a/route/v1/storage_test.go b/route/v1/storage_test.go
index c0d878e..eb1aa27 100644
--- a/route/v1/storage_test.go
+++ b/route/v1/storage_test.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 
 	model1 "github.com/ReCasaOS/CasaOS-LocalStorage/model"
@@ -181,3 +182,26 @@ func TestGetDiskListNeverOffersAnArrayMemberForFormatting(t *testing.T) {
 		}
 	}
 }
+
+// The body of the call that formats a disk used to be read with type assertions,
+// so a field of the wrong type, or a missing path, panicked in the handler. Each
+// is a bad request now, answered before anything reaches a disk -- the services
+// are not even set up here, so a call that went further would fail the test.
+func TestAMalformedAddStorageRequestIsABadRequest(t *testing.T) {
+	for _, body := range []string{
+		`{"path": "/dev/sdb", "name": "data", "format": "yes"}`,
+		`{"path": 42, "name": "data", "format": false}`,
+		`{"name": "data"}`,
+	} {
+		request := httptest.NewRequest(http.MethodPost, "/v1/storage", strings.NewReader(body))
+		request.Header.Set(echo.HeaderContentType, echo.MIMEApplicationJSON)
+		rec := httptest.NewRecorder()
+
+		if err := PostAddStorage(echo.New().NewContext(request, rec)); err != nil {
+			t.Fatalf("%s: %v", body, err)
+		}
+		if rec.Code != http.StatusBadRequest {
+			t.Errorf("%s: status %d, want 400: %s", body, rec.Code, rec.Body.String())
+		}
+	}
+}