diff --git a/engine/backends/proverif/proverif_backend.ml b/engine/backends/proverif/proverif_backend.ml
index 00b5620a6..a8c2c1791 100644
--- a/engine/backends/proverif/proverif_backend.ml
+++ b/engine/backends/proverif/proverif_backend.ml
@@ -114,14 +114,73 @@ module Print = struct
       method ty_int _ = string "bitstring"
 
       method! item' item =
+        let fun_and_reduc name variants =
+          let constructor = List.hd variants in
+          match constructor with
+          | None -> empty
+          | Some constructor ->
+              let field_prefix =
+                if constructor.is_record then empty
+                else print#concrete_ident name
+              in
+              let fun_args = constructor.arguments in
+              let fun_args_full =
+                separate_map
+                  (comma ^^ break 1)
+                  (fun (x, y, _z) ->
+                    field_prefix ^^ print#concrete_ident x ^^ string ": "
+                    ^^ print#ty_at Param_typ y)
+                  fun_args
+              in
+              let fun_args_names =
+                separate_map
+                  (comma ^^ break 1)
+                  (fst3 >> fun x -> field_prefix ^^ print#concrete_ident x)
+                  fun_args
+              in
+              let fun_args_types =
+                separate_map
+                  (comma ^^ break 1)
+                  (snd3 >> print#ty_at Param_typ)
+                  fun_args
+              in
+              let fun_line =
+                string "fun" ^^ space ^^ print#concrete_ident name
+                ^^ iblock parens fun_args_types
+                ^^ string ": state."
+              in
+              let reduc_line =
+                string "reduc forall " ^^ iblock Fn.id fun_args_full ^^ semi
+              in
+              let build_accessor (ident, ty, attr) =
+                string "accessor_" ^^ print#concrete_ident name ^^ underscore
+                ^^ print#concrete_ident ident
+                ^^ iblock parens
+                     (print#concrete_ident name ^^ iblock parens fun_args_names)
+                ^^ blank 1 ^^ equals ^^ blank 1 ^^ field_prefix
+                ^^ print#concrete_ident ident
+              in
+              let reduc_lines =
+                separate_map (dot ^^ hardline)
+                  (fun arg ->
+                    reduc_line ^^ nest 4 (hardline ^^ build_accessor arg))
+                  fun_args
+              in
+              fun_line ^^ hardline ^^ reduc_lines ^^ dot
+        in
         match item with
+        (* `fn`s are transformed into `letfun` process macros. *)
         | Fn { name; generics; body; params } ->
             let params_string =
               iblock parens (separate_map (comma ^^ break 1) print#param params)
             in
             string "letfun" ^^ space ^^ print#concrete_ident name
-            ^^ params_string ^^ string " = 0."
-        | _ -> string ""
+            ^^ params_string ^/^ equals
+            ^^ nest 4 (hardline ^^ print#expr_at Item_Fn_body body ^^ dot)
+        (* `struct` definitions are transformed into simple constructors and `reduc`s for accessing fields. *)
+        | Type { name; generics; variants; is_struct } ->
+            if is_struct then fun_and_reduc name variants else empty
+        | _ -> empty
     end
 
   include Api (struct
@@ -133,7 +192,7 @@ end
 let insert_top_level contents = contents ^ "\n\nprocess\n    0\n"
 
 (* Insert ProVerif code that will be necessary in any development.*)
-let insert_preamble contents = "channel c.\n\n" ^ contents
+let insert_preamble contents = "channel c.\ntype state.\n" ^ contents
 
 let translate m (bo : BackendOptions.t) (items : AST.item list) :
     Types.file list =
diff --git a/tests/Cargo.lock b/tests/Cargo.lock
index 5da19ad74..b96f861d3 100644
--- a/tests/Cargo.lock
+++ b/tests/Cargo.lock
@@ -265,6 +265,10 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "proverif-basic-structs"
+version = "0.1.0"
+
 [[package]]
 name = "proverif-minimal"
 version = "0.1.0"
diff --git a/tests/Cargo.toml b/tests/Cargo.toml
index d7879e02c..108febc8a 100644
--- a/tests/Cargo.toml
+++ b/tests/Cargo.toml
@@ -22,6 +22,7 @@ members = [
         "traits",
         "reordering",
         "nested-derefs",
-        "proverif-minimal"
+        "proverif-minimal",
+        "proverif-basic-structs"
 ]
 resolver = "2"
diff --git a/tests/proverif-basic-structs/Cargo.toml b/tests/proverif-basic-structs/Cargo.toml
new file mode 100644
index 000000000..183dae7e9
--- /dev/null
+++ b/tests/proverif-basic-structs/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "proverif-basic-structs"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+[package.metadata.hax-tests]
+into."pro-verif" = { broken = false, snapshot = "none" }
diff --git a/tests/proverif-basic-structs/src/lib.rs b/tests/proverif-basic-structs/src/lib.rs
new file mode 100644
index 000000000..2b278202c
--- /dev/null
+++ b/tests/proverif-basic-structs/src/lib.rs
@@ -0,0 +1,13 @@
+// Record struct with single field
+struct Ainitial {
+    x: u8,
+}
+
+// Record struct with multiple fields
+struct A {
+    one: usize,
+    two: usize,
+}
+
+// Non-record struct
+struct B(usize);