diff --git a/src/Swarm/TUI/Controller.hs b/src/Swarm/TUI/Controller.hs
index adb58afa3..93b8f9cef 100644
--- a/src/Swarm/TUI/Controller.hs
+++ b/src/Swarm/TUI/Controller.hs
@@ -830,13 +830,13 @@ handleREPLEventTyping = \case
             -- term (by `def` statements) to their requirements.
             -- E.g. if we had `def m = move end`, the reqCtx would
             -- record the fact that `m` needs the `move` capability.
-            -- We simply dump the entire `reqCtx` into the robot's
+            -- We simply add the entire `reqCtx` to the robot's
             -- context, so we can look up requirements if we later
             -- need to requirements-check an argument to `build` or
             -- `reprogram` at runtime.  See the discussion at
             -- https://github.com/swarm-game/swarm/pull/827 for more
             -- details.
-            . (gameState . baseRobot . robotContext . defReqs .~ reqCtx)
+            . (gameState . baseRobot . robotContext . defReqs <>~ reqCtx)
             -- Set up the robot's CESK machine to evaluate/execute the
             -- given term, being sure to initialize the CESK machine
             -- environment and store from the top-level context.
diff --git a/test/integration/Main.hs b/test/integration/Main.hs
index 6c8f89ac9..acde2ca50 100644
--- a/test/integration/Main.hs
+++ b/test/integration/Main.hs
@@ -5,7 +5,7 @@
 -- | Swarm integration tests
 module Main where
 
-import Control.Lens (Ixed (ix), to, use, view, (&), (.~), (<&>), (^.), (^..), (^?!))
+import Control.Lens (Ixed (ix), to, use, view, (&), (.~), (<&>), (<>~), (^.), (^..), (^?!))
 import Control.Monad (filterM, forM_, unless, void, when)
 import Control.Monad.State (StateT (runStateT), gets)
 import Control.Monad.Trans.Except (runExceptT)
@@ -249,10 +249,10 @@ testScenarioSolution _ci _em =
         Just sol@(ProcessedTerm _ _ _ reqCtx) -> do
           let gs' =
                 gs
-                  -- See #827 for an explanation of why it's important to set
+                  -- See #827 for an explanation of why it's important to add to
                   -- the robotContext defReqs here (and also why this will,
                   -- hopefully, eventually, go away).
-                  & baseRobot . robotContext . defReqs .~ reqCtx
+                  & baseRobot . robotContext . defReqs <>~ reqCtx
                   & baseRobot . machine .~ initMachine sol Ctx.empty emptyStore
           m <- timeout (time s) (snd <$> runStateT playUntilWin gs')
           case m of