diff --git a/lib/Monomorphization.ml b/lib/Monomorphization.ml
index b3bd1175..d5aa81f3 100644
--- a/lib/Monomorphization.ml
+++ b/lib/Monomorphization.ml
@@ -379,8 +379,8 @@ module Gen = struct
     let doc =
       let open PPrint in
       let open PrintAst in
-      separate_map underscore print_typ ts ^^ underscore ^^
-      separate_map underscore print_expr cgs
+      separate_map underscore print_typ ts ^^
+      (if cgs = [] then empty else underscore ^^ separate_map underscore print_expr cgs)
     in
     fst lid, snd lid ^ KPrint.bsprintf "__%a" PrintCommon.pdoc doc
 
diff --git a/test/.hints/Rust1.fst.hints b/test/.hints/Rust1.fst.hints
index 9fcb1a1f..d8f31467 100644
--- a/test/.hints/Rust1.fst.hints
+++ b/test/.hints/Rust1.fst.hints
@@ -20,7 +20,7 @@
         "typing_FStar.Monotonic.HyperStack.get_hmap"
       ],
       0,
-      "5bb324f2cfa11752ab6a4b007bdd2ac9"
+      "d8d782168aeb290839dc8db99793893b"
     ],
     [
       "Rust1.two",
@@ -41,7 +41,7 @@
         "typing_FStar.Monotonic.HyperStack.get_hmap"
       ],
       0,
-      "19af3f16124ed6131ebd118a1645f272"
+      "b977b9a8e679010dd7db6093c2b24d8a"
     ],
     [
       "Rust1.zero",
@@ -62,7 +62,7 @@
         "typing_FStar.Monotonic.HyperStack.get_hmap"
       ],
       0,
-      "d085467eb557cb757d2b85c57ebf2d84"
+      "f86c73e1af7e81dadb23c04c7c9f2a29"
     ],
     [
       "Rust1.doesnt_work",
@@ -150,7 +150,7 @@
         "typing_LowStar.Monotonic.Buffer.loc_buffer"
       ],
       0,
-      "91f166bd89ddce81d6c4629fdda8bac7"
+      "d6ead5099b52df6e78f527a435081340"
     ],
     [
       "Rust1.does_work",
@@ -238,7 +238,7 @@
         "typing_LowStar.Monotonic.Buffer.loc_buffer"
       ],
       0,
-      "fe0681b3f23222e6fe18d1c809712105"
+      "15b8216a10f04a5bca9b51bdab9afc07"
     ],
     [
       "Rust1.fully_static",
@@ -327,7 +327,7 @@
         "typing_LowStar.Monotonic.Buffer.loc_buffer"
       ],
       0,
-      "28f783251277dfe18bc75dccb61fd8a4"
+      "fc56150d57736c34acb5641ad70c2f88"
     ],
     [
       "Rust1.main",
@@ -416,7 +416,7 @@
         "typing_LowStar.Monotonic.Buffer.loc_buffer"
       ],
       0,
-      "68a280be773e96f4eb3f61ae14d6c637"
+      "7a928ff143175d99fb65b5f56469a5e5"
     ]
   ]
 ]
\ No newline at end of file