diff --git a/Project.toml b/Project.toml
index 2219a90..c6dd2c8 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "Infinities"
 uuid = "e1ba4f0e-776d-440f-acd9-e1d2e9742647"
 authors = ["Sheehan Olver <solver@mac.com>"]
-version = "0.1.8"
+version = "0.1.9"
 
 [compat]
 Aqua = "0.8"
diff --git a/src/Infinities.jl b/src/Infinities.jl
index 3bd8cd7..e6ff365 100644
--- a/src/Infinities.jl
+++ b/src/Infinities.jl
@@ -243,7 +243,7 @@ max(::RealInfinity, ::Infinity) = ∞
 min(::Infinity, x::RealInfinity) = x
 max(::Infinity, x::RealInfinity) = ∞
 
-
+Base.to_index(i::RealInfinity) = convert(Integer, i)
 
 ######
 # ComplexInfinity
diff --git a/test/runtests.jl b/test/runtests.jl
index 8768545..695317f 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -205,6 +205,8 @@ end
             @test convert(Float16, -∞) ≡ Float16(-∞) ≡ -Inf16
             @test convert(BigFloat, -∞)::BigFloat == BigFloat(-∞)::BigFloat == -BigFloat(Inf)
         end
+
+        @test Base.to_index(RealInfinity()) ≡ ℵ₀
     end
 
     @testset "ComplexInfinity" begin