diff --git a/src/test/ui/lint/unused_parens_json_suggestion.fixed b/src/test/ui/lint/unused_parens_json_suggestion.fixed
index 5408a7cab7f..757ad933a1f 100644
--- a/src/test/ui/lint/unused_parens_json_suggestion.fixed
+++ b/src/test/ui/lint/unused_parens_json_suggestion.fixed
@@ -1,4 +1,4 @@
-// compile-flags: --error-format pretty-json -Zunstable-options
+// compile-flags: --error-format json -Zunstable-options
 // run-rustfix
 
 // The output for humans should just highlight the whole span without showing
diff --git a/src/test/ui/lint/unused_parens_json_suggestion.rs b/src/test/ui/lint/unused_parens_json_suggestion.rs
index ca421523ccd..173cd555450 100644
--- a/src/test/ui/lint/unused_parens_json_suggestion.rs
+++ b/src/test/ui/lint/unused_parens_json_suggestion.rs
@@ -1,4 +1,4 @@
-// compile-flags: --error-format pretty-json -Zunstable-options
+// compile-flags: --error-format json -Zunstable-options
 // run-rustfix
 
 // The output for humans should just highlight the whole span without showing
diff --git a/src/test/ui/lint/unused_parens_json_suggestion.stderr b/src/test/ui/lint/unused_parens_json_suggestion.stderr
index 54baade36e6..c503c100808 100644
--- a/src/test/ui/lint/unused_parens_json_suggestion.stderr
+++ b/src/test/ui/lint/unused_parens_json_suggestion.stderr
@@ -1,96 +1,4 @@
-{
-  "message": "unnecessary parentheses around assigned value",
-  "code": {
-    "code": "unused_parens",
-    "explanation": null
-  },
-  "level": "error",
-  "spans": [
-    {
-      "file_name": "$DIR/unused_parens_json_suggestion.rs",
-      "byte_start": 603,
-      "byte_end": 616,
-      "line_start": 16,
-      "line_end": 16,
-      "column_start": 14,
-      "column_end": 27,
-      "is_primary": true,
-      "text": [
-        {
-          "text": "    let _a = (1 / (2 + 3));
-          "highlight_start": 14,
-          "highlight_end": 27
-        }
-      ],
-      "label": null,
-      "suggested_replacement": null,
-      "suggestion_applicability": null,
-      "expansion": null
-    }
-  ],
-  "children": [
-    {
-      "message": "lint level defined here",
-      "code": null,
-      "level": "note",
-      "spans": [
-        {
-          "file_name": "$DIR/unused_parens_json_suggestion.rs",
-          "byte_start": 421,
-          "byte_end": 434,
-          "line_start": 10,
-          "line_end": 10,
-          "column_start": 9,
-          "column_end": 22,
-          "is_primary": true,
-          "text": [
-            {
-              "text": "#![deny(unused_parens)]",
-              "highlight_start": 9,
-              "highlight_end": 22
-            }
-          ],
-          "label": null,
-          "suggested_replacement": null,
-          "suggestion_applicability": null,
-          "expansion": null
-        }
-      ],
-      "children": [],
-      "rendered": null
-    },
-    {
-      "message": "remove these parentheses",
-      "code": null,
-      "level": "help",
-      "spans": [
-        {
-          "file_name": "$DIR/unused_parens_json_suggestion.rs",
-          "byte_start": 603,
-          "byte_end": 616,
-          "line_start": 16,
-          "line_end": 16,
-          "column_start": 14,
-          "column_end": 27,
-          "is_primary": true,
-          "text": [
-            {
-              "text": "    let _a = (1 / (2 + 3));
-              "highlight_start": 14,
-              "highlight_end": 27
-            }
-          ],
-          "label": null,
-          "suggested_replacement": "1 / (2 + 3)",
-          "suggestion_applicability": "MachineApplicable",
-          "expansion": null
-        }
-      ],
-      "children": [],
-      "rendered": null
-    }
-  ],
-  "rendered": "error: unnecessary parentheses around assigned value
+{"message":"unnecessary parentheses around assigned value","code":{"code":"unused_parens","explanation":null},"level":"error","spans":[{"file_name":"$DIR/unused_parens_json_suggestion.rs","byte_start":596,"byte_end":609,"line_start":16,"line_end":16,"column_start":14,"column_end":27,"is_primary":true,"text":[{"text":"    let _a = (1 / (2 + 3));
   --> $DIR/unused_parens_json_suggestion.rs:16:14
    |
 LL |     let _a = (1 / (2 + 3));
@@ -102,15 +10,7 @@ note: lint level defined here
 LL | #![deny(unused_parens)]
    |         ^^^^^^^^^^^^^
 
-"
-}
-{
-  "message": "aborting due to previous error",
-  "code": null,
-  "level": "error",
-  "spans": [],
-  "children": [],
-  "rendered": "error: aborting due to previous error
+"}
+{"message":"aborting due to previous error","code":null,"level":"error","spans":[],"children":[],"rendered":"error: aborting due to previous error
 
-"
-}
+"}