diff --git a/Batteries/Data/Range/Lemmas.lean b/Batteries/Data/Range/Lemmas.lean
index a075e0b6b4..3fd893daa9 100644
--- a/Batteries/Data/Range/Lemmas.lean
+++ b/Batteries/Data/Range/Lemmas.lean
@@ -57,12 +57,15 @@ theorem forIn'_eq_forIn_range' [Monad m] (r : Std.Range)
   suffices ∀ H, forIn' [start:stop:step] init f = forIn (L.pmap Subtype.mk H) init f' from this _
   intro H; dsimp only [forIn', Range.forIn']
   if h : start < stop then
-    simp [numElems, Nat.not_le.2 h, L]; split
+    simp only [numElems, Nat.not_le.2 h, ↓reduceIte, L]; split
     · subst step
       suffices ∀ n H init,
           forIn'.loop start stop 0 f n start (Nat.le_refl _) init =
           forIn ((List.range' start n 0).pmap Subtype.mk H) init f' from this _ ..
-      intro n; induction n with (intro H init; unfold forIn'.loop; simp [*])
+      intro n; induction n with
+        (intro H init
+         unfold forIn'.loop
+         simp only [↓reduceDIte, Nat.add_zero, List.pmap, List.forIn_cons, List.forIn_nil, h])
       | succ n ih => simp [ih (List.forall_mem_cons.1 H).2]; rfl
     · next step0 =>
       have hstep := Nat.pos_of_ne_zero step0
@@ -84,10 +87,15 @@ theorem forIn'_eq_forIn_range' [Monad m] (r : Std.Range)
           have ih := ih _ _ (Nat.le_trans hle (Nat.le_add_right ..))
             (List.forall_mem_cons.1 H).2 (Nat.le_of_succ_le_succ h1) fun i => by
               rw [Nat.add_right_comm, Nat.add_assoc, ← Nat.mul_succ, h2, Nat.succ_le_succ_iff]
-          have := h2 0; simp at this
-          rw [forIn'.loop]; simp [this, ih]; rfl
+          have := h2 0
+          simp only [Nat.mul_zero, Nat.add_zero, Nat.le_zero_eq, Nat.add_one_ne_zero, iff_false,
+            Nat.not_le] at this
+          rw [forIn'.loop]
+          simp only [this, ↓reduceDIte, ih, List.pmap, List.forIn_cons]
+          rfl
   else
-    simp [List.range', h, numElems_stop_le_start ⟨start, stop, step⟩ (Nat.not_lt.1 h), L]
+    simp only [numElems_stop_le_start ⟨start, stop, step⟩ (Nat.not_lt.1 h), List.range'_zero,
+      List.pmap, List.forIn_nil, L]
     cases stop <;> unfold forIn'.loop <;> simp [List.forIn', h]
 
 theorem forIn_eq_forIn_range' [Monad m] (r : Std.Range)