diff --git a/src/stages/ast_simplified/PP.ml b/src/stages/ast_simplified/PP.ml
index ac7c4bafe..71ec1d6ae 100644
--- a/src/stages/ast_simplified/PP.ml
+++ b/src/stages/ast_simplified/PP.ml
@@ -1,3 +1,4 @@
+[@@@coverage exclude_file]
 open Types
 open PP_helpers
 open Format
diff --git a/src/stages/ast_typed/PP.ml b/src/stages/ast_typed/PP.ml
index 45a4ddfec..ef0e96a39 100644
--- a/src/stages/ast_typed/PP.ml
+++ b/src/stages/ast_typed/PP.ml
@@ -1,3 +1,4 @@
+[@@@coverage exclude_file]
 open Types
 open Format
 open PP_helpers
diff --git a/src/stages/mini_c/PP.ml b/src/stages/mini_c/PP.ml
index 054d88cb9..9b3e7fa3d 100644
--- a/src/stages/mini_c/PP.ml
+++ b/src/stages/mini_c/PP.ml
@@ -1,3 +1,4 @@
+[@@@coverage exclude_file]
 open Simple_utils.PP_helpers
 open Types
 open Format