diff --git a/test/arrays.jl b/test/arrays.jl
index 925ed1459..1778237f0 100644
--- a/test/arrays.jl
+++ b/test/arrays.jl
@@ -409,3 +409,8 @@ end
     @test_throws BoundsError k[-1]
     @test_throws BoundsError k[4]
 end
+
+@testset "similar term #991"
+    @variables x[1:3]
+    @test substitute(x[1:2] .* x[3], Dict(x => [1, 2, 3])) == [3, 6]
+end
\ No newline at end of file