diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 689d1079eef..962a31d5023 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -2602,7 +2602,7 @@
         "code": 4083
     },
     "Conflicting definitions for '{0}' found at '{1}' and '{2}'. Consider installing a specific version of this library to resolve the conflict.": {
-        "category": "Message",
+        "category": "Error",
         "code": 4090
     },
     "Parameter '{0}' of index signature from exported interface has or is using name '{1}' from private module '{2}'.": {
diff --git a/tests/baselines/reference/library-reference-5.errors.txt b/tests/baselines/reference/library-reference-5.errors.txt
index 173865ed82d..8aead70ff0b 100644
--- a/tests/baselines/reference/library-reference-5.errors.txt
+++ b/tests/baselines/reference/library-reference-5.errors.txt
@@ -1,4 +1,4 @@
-/node_modules/bar/index.d.ts(1,23): message TS4090: Conflicting definitions for 'alpha' found at '/node_modules/bar/node_modules/alpha/index.d.ts' and '/node_modules/foo/node_modules/alpha/index.d.ts'. Consider installing a specific version of this library to resolve the conflict.
+/node_modules/bar/index.d.ts(1,23): error TS4090: Conflicting definitions for 'alpha' found at '/node_modules/bar/node_modules/alpha/index.d.ts' and '/node_modules/foo/node_modules/alpha/index.d.ts'. Consider installing a specific version of this library to resolve the conflict.
 
 
 ==== /src/root.ts (0 errors) ====
@@ -17,7 +17,7 @@
 ==== /node_modules/bar/index.d.ts (1 errors) ====
     /// <reference types="alpha" />
                           ~~~~~
-!!! message TS4090: Conflicting definitions for 'alpha' found at '/node_modules/bar/node_modules/alpha/index.d.ts' and '/node_modules/foo/node_modules/alpha/index.d.ts'. Consider installing a specific version of this library to resolve the conflict.
+!!! error TS4090: Conflicting definitions for 'alpha' found at '/node_modules/bar/node_modules/alpha/index.d.ts' and '/node_modules/foo/node_modules/alpha/index.d.ts'. Consider installing a specific version of this library to resolve the conflict.
     declare var bar: any;
     
 ==== /node_modules/bar/node_modules/alpha/index.d.ts (0 errors) ====