diff --git a/gcc/testsuite/g++.dg/modules/pr99023_b.X b/gcc/testsuite/g++.dg/modules/pr99023_b.X
index 3d82f34868b75df69094c3da4b23672d7365dd0b..ca5f32e5bccbc5118d6413732801e39942598f72 100644
--- a/gcc/testsuite/g++.dg/modules/pr99023_b.X
+++ b/gcc/testsuite/g++.dg/modules/pr99023_b.X
@@ -3,5 +3,5 @@
 
 // { dg-prune-output {linker input file unused} }
 
-// { dg-regexp {[^\n]*: note: include '[^\n]*/initializer_list' translated to import\n} }
+// { dg-regexp {[^\n]*: note: include '[^\n]*[/\\]initializer_list' translated to import\n} }
 NO DO NOT COMPILE