diff --git a/src/arrays.jl b/src/arrays.jl
index ce6504eae..4915b94fb 100644
--- a/src/arrays.jl
+++ b/src/arrays.jl
@@ -99,6 +99,14 @@ function arguments(a::ArrayOp)
     arguments(a.term)
 end
 
+function similarterm(a::ArrayOp, f, args, type; metadata=nothing)
+    res = f(args...)
+    if res isa Symbolic && metadata !== nothing
+        res = SymbolicUtils.metadata(res, metadata)
+    end
+    res
+end
+
 function Base.isequal(a::ArrayOp, b::ArrayOp)
     a === b && return true
     isequal(a.shape, b.shape) &&
diff --git a/test/arrays.jl b/test/arrays.jl
index 24497a0a1..98da87837 100644
--- a/test/arrays.jl
+++ b/test/arrays.jl
@@ -413,3 +413,8 @@ end
     @test_throws BoundsError k[-1]
     @test_throws BoundsError k[4]
 end
+
+@testset "similar term #991" begin
+    @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