diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 7bf59202..502cc604 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -59,3 +59,9 @@ parameters:
 			identifier: argument.type
 			count: 1
 			path: src/Prophecy/Prophecy/MethodProphecy.php
+
+		-
+			message: '#^Possibly invalid array key type mixed\.$#'
+			identifier: offsetAccess.invalidOffset
+			count: 1
+			path: src/Prophecy/Util/ExportUtil.php