diff --git a/src/Diffusers.jl b/src/Diffusers.jl
index f4d683a..eeb80a2 100644
--- a/src/Diffusers.jl
+++ b/src/Diffusers.jl
@@ -1,12 +1,6 @@
 module Diffusers
 
 include("BetaSchedules/BetaSchedules.jl")
-
-# abtract types
-include("Schedulers.jl")
-
-# concrete types
-include("DDPM.jl")
-# include("DDIM.jl")
+include("Schedulers/Schedulers.jl")
 
 end # module Diffusers
diff --git a/src/Schedulers.jl b/src/Schedulers.jl
deleted file mode 100644
index 1a1abe4..0000000
--- a/src/Schedulers.jl
+++ /dev/null
@@ -1,29 +0,0 @@
-abstract type Scheduler end
-
-"""
-Add noise to clean data using the forward diffusion process.
-
-## Input
-  * `scheduler::Scheduler`: scheduler to use
-  * `x₀::AbstractArray`: clean data to add noise to
-  * `ϵ::AbstractArray`: noise to add to clean data
-  * `t::AbstractArray`: timesteps used to weight the noise
-
-## Output
-  * `xₜ::AbstractArray`: noisy data at the given timesteps
-"""
-function add_noise(
-  scheduler::Scheduler,
-  x₀::AbstractArray,
-  ϵ::AbstractArray,
-  t::AbstractArray,
-)
-  ⎷α̅ₜ = scheduler.⎷α̅[t]
-  ⎷β̅ₜ = scheduler.⎷β̅[t]
-
-  # noisify clean data
-  # arxiv:2006.11239 Eq. 4
-  xₜ = ⎷α̅ₜ' .* x₀ + ⎷β̅ₜ' .* ϵ
-
-  return xₜ
-end
diff --git a/src/DDPM.jl b/src/Schedulers/DDPM.jl
similarity index 80%
rename from src/DDPM.jl
rename to src/Schedulers/DDPM.jl
index d8aec81..1f655e7 100644
--- a/src/DDPM.jl
+++ b/src/Schedulers/DDPM.jl
@@ -1,4 +1,4 @@
-include("Schedulers.jl")
+abstract type Scheduler end
 
 """
 Denoising Diffusion Probabilistic Models (DDPM) scheduler.
@@ -65,6 +65,34 @@ function DDPM(V::DataType, β::AbstractVector)
   )
 end
 
+"""
+Add noise to clean data using the forward diffusion process.
+
+## Input
+  * `scheduler::Scheduler`: scheduler to use
+  * `x₀::AbstractArray`: clean data to add noise to
+  * `ϵ::AbstractArray`: noise to add to clean data
+  * `t::AbstractArray`: timesteps used to weight the noise
+
+## Output
+  * `xₜ::AbstractArray`: noisy data at the given timesteps
+"""
+function add_noise(
+  scheduler::DDPM,
+  x₀::AbstractArray,
+  ϵ::AbstractArray,
+  t::AbstractArray,
+)
+  ⎷α̅ₜ = scheduler.⎷α̅[t]
+  ⎷β̅ₜ = scheduler.⎷β̅[t]
+
+  # noisify clean data
+  # arxiv:2006.11239 Eq. 4
+  xₜ = ⎷α̅ₜ' .* x₀ + ⎷β̅ₜ' .* ϵ
+
+  return xₜ
+end
+
 """
 Remove noise from model output using the backward diffusion process.
 
diff --git a/src/Schedulers/Schedulers.jl b/src/Schedulers/Schedulers.jl
new file mode 100644
index 0000000..f765611
--- /dev/null
+++ b/src/Schedulers/Schedulers.jl
@@ -0,0 +1,9 @@
+module Schedulers
+
+include("DDPM.jl")
+
+export DDPM
+
+export add_noise, step
+
+end # module Schedulers