diff --git a/eca-editor.el b/eca-editor.el
index be4bb70..08c6163 100644
--- a/eca-editor.el
+++ b/eca-editor.el
@@ -62,12 +62,18 @@ If URI is nil find all diagnostics otherwise filter to that uri."
                                  (end-r (lsp-get range :end)))
                             (push (list :uri uri
                                         :severity (eca-editor--lsp-to-eca-severity (lsp-get it :severity))
-                                        :code (lsp-get it :code)
+                                        :code (when-let ((code (lsp-get it :code)))
+                                                (if (symbolp code)
+                                                    (symbol-name code)
+                                                  (format "%s" code)))
                                         :range (list :start (list :line (lsp-get start-r :line)
                                                                   :character (lsp-get start-r :character))
                                                      :end (list :line (lsp-get end-r :line)
                                                                 :character (lsp-get end-r :character)))
-                                        :source (lsp-get it :source)
+                                        :source (when-let ((source (lsp-get it :source)))
+                                                  (if (symbolp source)
+                                                      (symbol-name source)
+                                                    (format "%s" source)))
                                         :message (lsp-get it :message))
                                   eca-diagnostics))
                           lsp-diagnostics)))
@@ -91,12 +97,18 @@ If URI is nil find all diagnostics otherwise filter to that uri."
                 (end-col (current-column)))
            (list :uri (eca--path-to-uri (buffer-file-name (flymake-diagnostic-buffer it)))
                  :severity (eca-editor--flymake-to-eca-severity (flymake-diagnostic-type it))
-                 :code (flymake-diagnostic-code it)
+                 :code (when-let ((code (flymake-diagnostic-code it)))
+                         (if (symbolp code)
+                             (symbol-name code)
+                           (format "%s" code)))
                  :range (list :start (list :line beg-line
                                            :character beg-col)
                               :end (list :line end-line
                                          :character end-col))
-                 :source (flymake-diagnostic-backend it)
+                 :source (when-let ((backend (flymake-diagnostic-backend it)))
+                           (if (symbolp backend)
+                               (symbol-name backend)
+                             (format "%s" backend)))
                  :message (flymake-diagnostic-text it)))))
      (flymake--project-diagnostics))))