From 6798fb05a9410a20d17676b1449d2bcc5fd36594 Mon Sep 17 00:00:00 2001
From: Troels Henriksen <athas@sigkill.dk>
Date: Fri, 25 Aug 2023 10:24:35 +0200
Subject: [PATCH] Fix #2011.

---
 src/Language/Futhark/Interpreter.hs | 4 +++-
 tests/issue2011.fut                 | 9 +++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 tests/issue2011.fut

diff --git a/src/Language/Futhark/Interpreter.hs b/src/Language/Futhark/Interpreter.hs
index f34979abdf..86fff8fb88 100644
--- a/src/Language/Futhark/Interpreter.hs
+++ b/src/Language/Futhark/Interpreter.hs
@@ -1152,7 +1152,9 @@ evalModExp env (ModDecs ds _) = do
   Env terms types <- foldM evalDec env ds
   -- Remove everything that was present in the original Env.
   pure
-    ( Env terms types,
+    ( Env
+        (terms `M.difference` envTerm env)
+        (types `M.difference` envType env),
       Module $
         Env
           (terms `M.difference` envTerm env)
diff --git a/tests/issue2011.fut b/tests/issue2011.fut
new file mode 100644
index 0000000000..9dd9b70bf5
--- /dev/null
+++ b/tests/issue2011.fut
@@ -0,0 +1,9 @@
+-- ==
+-- input {}
+-- output { 4u64 }
+
+module mod: {module x: integral} = {
+  module x = u64
+}
+
+def main = u64.i64 4