diff --git a/marietje/songs/templates/songs/upload.html b/marietje/songs/templates/songs/upload.html
index b28f8e7..c2d734e 100644
--- a/marietje/songs/templates/songs/upload.html
+++ b/marietje/songs/templates/songs/upload.html
@@ -179,13 +179,14 @@
                         }).catch(e => {
                             console.log(e);
                             if (e instanceof Response) {
-                                try {
-                                    e.json().then(data => {
-                                        this.fileObjects[i].error_message = data.errorMessage;
-                                        this.fileObjects[i].success = false;
-                                    });
-                                } catch {
-                                    this.fileObjects[i].error_message = "An exception occurred while uploading this file, please try again.";
+                                // Intercept an HTTP 413 error (entity too large), as this might
+                                // be thrown by a (reverse) proxy server and its payload is not
+                                // nicely formatted as the code below expects.
+                                if (e.status === 413) {
+                                    this.fileObjects[i].error_message = "The song you tried to upload is too large in size. (HTTP 413 error)";
+                                    this.fileObjects[i].success = false;
+                                } else {
+                                    this.fileObjects[i].error_message = `${e.statusText} (${e.status})`;
                                     this.fileObjects[i].success = false;
                                 }
                             } else {