diff --git a/base/array.jl b/base/array.jl
index f247c8a32dbee..10b2f35042787 100644
--- a/base/array.jl
+++ b/base/array.jl
@@ -687,9 +687,10 @@ function collect_to!(dest::AbstractArray{T}, itr, offs, st) where T
             return collect_to!(new, itr, i+1, st)
         end
     end
-    i-1 < length(dest) &&
+    lastidx = lastindex(dest)
+    i-1 < lastidx &&
         throw(ErrorException("iterator returned fewer elements than its declared length"))
-    i-1 > length(dest) &&
+    i-1 > lastidx &&
         throw(ErrorException("iterator returned more elements than its declared length"))
     return dest
 end
diff --git a/test/arrayops.jl b/test/arrayops.jl
index c2d3469ac2118..dfcb774beb85f 100644
--- a/test/arrayops.jl
+++ b/test/arrayops.jl
@@ -2546,7 +2546,8 @@ end
     @test_throws ErrorException collect(InvalidIter2())
     @test_throws ErrorException collect(Any, InvalidIter2())
     @test_throws ErrorException collect(Int, InvalidIter2())
-    @test_throws ErrorException [x for x in InvalidIter2()]
-    # Should also throw ErrorException
-    @test_broken length(Int[x for x in InvalidIter2()]) != 2
+    # These cases cannot be tested without writing to invalid memory
+    # unless the function checked bounds on each iteration (#29458)
+    # @test_throws ErrorException [x for x in InvalidIter2()]
+    # @test_throws ErrorException Int[x for x in InvalidIter2()]
 end
\ No newline at end of file