diff --git a/lib/UseAnalysis.ml b/lib/UseAnalysis.ml
index 1689cb06..cf75e97a 100644
--- a/lib/UseAnalysis.ml
+++ b/lib/UseAnalysis.ml
@@ -207,7 +207,7 @@ let use_mark_to_remove_or_ignore final = object (self)
       (* Definitely unused, except we can't generate let _ = ignore (bufcreate
          ...) -- this is a bad idea, as it'll force the hoisting phase to hoist
          the bufcreate back into a let-binding, which will then be named "buf". *)
-      else if not (is_bufcreate e1) then
+      else if not (is_bufcreate e1) && Helpers.is_value e1 then
         ELet ({ node = { b.node with meta = Some MetaSequence }; typ = TUnit; meta = []},
           push_ignore e1,
           e2)
diff --git a/test/KrmlTrue.fst b/test/KrmlTrue.fst
new file mode 100644
index 00000000..0aa53ffb
--- /dev/null
+++ b/test/KrmlTrue.fst
@@ -0,0 +1,15 @@
+module KrmlTrue
+
+let some_effectul_function (x:unit) : Dv unit = ()
+
+let test (x:unit)
+: Dv unit
+= let res =
+    let _ = some_effectul_function x in
+    true
+  in
+  some_effectul_function x
+
+let main () =
+  test ();
+  0l
diff --git a/test/Makefile b/test/Makefile
index e66d88e5..7b04a8e4 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -60,7 +60,9 @@ ifneq ($(RECENT_GCC),"yes")
 endif
 
 CUSTOM		= count-eq count-uu check-unused check-no-constructor check-no-erased \
-  check-right-file count-deref check-global-init check-useless-alias check-inline-let
+  check-right-file count-deref check-global-init check-useless-alias check-inline-let \
+  check-comment check-ignore
+
 ifneq ($(CRYPTO),)
   CRYPTO_WASM_FILES=Crypto.Symmetric.Chacha20.wasm-test
 endif
@@ -247,6 +249,9 @@ check-comment: $(OUTPUT_DIR)/Comment.exe
 	grep -q XXX3 $(OUTPUT_DIR)/Comment.out/Comment.c && \
 	true
 
+check-ignore: $(OUTPUT_DIR)/KrmlTrue.exe
+	! grep -q IGNORE $(OUTPUT_DIR)/KrmlTrue.out/KrmlTrue.c
+
 clean:
 	rm -rf $(WEB_DIR) .output