diff --git a/Project.toml b/Project.toml
index 758e95243..23566ffaf 100644
--- a/Project.toml
+++ b/Project.toml
@@ -9,6 +9,7 @@ Bijectors = "76274a88-744f-5084-9051-94815aaf08c4"
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
 Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 MacroTools = "1914dd2f-81c6-5fcd-8719-6d5c9610ff09"
+MeasureTheory = "eadaa1a4-d27c-401d-8699-e962e1bbc33b"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 ZygoteRules = "700de1a5-db45-46bc-99cf-38207098b444"
 
diff --git a/src/DynamicPPL.jl b/src/DynamicPPL.jl
index a46c941a1..4d64cccd6 100644
--- a/src/DynamicPPL.jl
+++ b/src/DynamicPPL.jl
@@ -129,5 +129,6 @@ include("prob_macro.jl")
 include("compat/ad.jl")
 include("loglikelihoods.jl")
 include("submodel_macro.jl")
+include("measuretheory.jl")
 
 end # module
diff --git a/src/measuretheory.jl b/src/measuretheory.jl
new file mode 100644
index 000000000..20efa8b30
--- /dev/null
+++ b/src/measuretheory.jl
@@ -0,0 +1,70 @@
+using MeasureTheory: MeasureTheory
+
+# src/compiler.jl
+# Allow `AbstractMeasure` on the RHS of `~`.
+check_tilde_rhs(x::MeasureTheory.AbstractMeasure) = x
+
+# src/utils.jl
+# Linearization.
+vectorize(d::MeasureTheory.AbstractMeasure, x::Real) = [x]
+vectorize(d::MeasureTheory.AbstractMeasure, x::AbstractArray{<:Real}) = copy(vec(x))
+
+function reconstruct(d::MeasureTheory.AbstractMeasure, x::AbstractVector{<:Real})
+    return _reconstruct(d, x, MeasureTheory.sampletype(d))
+end
+
+# TODO: Higher dims. What to do? Do we have access to size, e.g. for `LKJ` we should have?
+function _reconstruct(
+    d::MeasureTheory.AbstractMeasure, x::AbstractVector{<:Real}, ::Type{<:Real}
+)
+    return x[1]
+end
+function _reconstruct(
+    d::MeasureTheory.AbstractMeasure,
+    x::AbstractVector{<:Real},
+    ::Type{<:AbstractVector{<:Real}},
+)
+    return x
+end
+
+# src/context_implementations.jl
+# assume
+function assume(dist::MeasureTheory.AbstractMeasure, vn::VarName, vi)
+    r = vi[vn]
+    # TODO: Transformed variables.
+    return r, MeasureTheory.logdensity(dist, r)
+end
+
+function assume(
+    rng::Random.AbstractRNG,
+    sampler::Union{SampleFromPrior,SampleFromUniform},
+    dist::MeasureTheory.AbstractMeasure,
+    vn::VarName,
+    vi,
+)
+    if haskey(vi, vn)
+        # Always overwrite the parameters with new ones for `SampleFromUniform`.
+        if sampler isa SampleFromUniform || is_flagged(vi, vn, "del")
+            unset_flag!(vi, vn, "del")
+            r = init(rng, dist, sampler)
+            vi[vn] = vectorize(dist, r)
+            settrans!(vi, false, vn)
+            setorder!(vi, vn, get_num_produce(vi))
+        else
+            r = vi[vn]
+        end
+    else
+        r = init(rng, dist, sampler)
+        push!(vi, vn, r, dist, sampler)
+        settrans!(vi, false, vn)
+    end
+
+    # TODO: Transformed variables.
+    return r, MeasureTheory.logdensity(dist, r)
+end
+
+# observe
+function observe(right::MeasureTheory.AbstractMeasure, left, vi)
+    increment_num_produce!(vi)
+    return MeasureTheory.logdensity(right, left)
+end
diff --git a/src/varinfo.jl b/src/varinfo.jl
index 64c122dc2..450c121fe 100644
--- a/src/varinfo.jl
+++ b/src/varinfo.jl
@@ -43,7 +43,7 @@ barrier to make the rest of the sampling type stable.
 """
 struct Metadata{
     TIdcs<:Dict{<:VarName,Int},
-    TDists<:AbstractVector{<:Distribution},
+    TDists<:AbstractVector,
     TVN<:AbstractVector{<:VarName},
     TVal<:AbstractVector{<:Real},
     TGIds<:AbstractVector{Set{Selector}},
@@ -192,7 +192,7 @@ function Metadata()
         Vector{VarName}(),
         Vector{UnitRange{Int}}(),
         vals,
-        Vector{Distribution}(),
+        Vector(),
         Vector{Set{Selector}}(),
         Vector{Int}(),
         flags,
@@ -1098,7 +1098,7 @@ end
 Push a new random variable `vn` with a sampled value `r` from a distribution `dist` to
 the `VarInfo` `vi`.
 """
-function push!(vi::AbstractVarInfo, vn::VarName, r, dist::Distribution)
+function push!(vi::AbstractVarInfo, vn::VarName, r, dist)
     return push!(vi, vn, r, dist, Set{Selector}([]))
 end
 
@@ -1110,12 +1110,10 @@ from a distribution `dist` to `VarInfo` `vi`.
 
 The sampler is passed here to invalidate its cache where defined.
 """
-function push!(vi::AbstractVarInfo, vn::VarName, r, dist::Distribution, spl::Sampler)
+function push!(vi::AbstractVarInfo, vn::VarName, r, dist, spl::Sampler)
     return push!(vi, vn, r, dist, spl.selector)
 end
-function push!(
-    vi::AbstractVarInfo, vn::VarName, r, dist::Distribution, spl::AbstractSampler
-)
+function push!(vi::AbstractVarInfo, vn::VarName, r, dist, spl::AbstractSampler)
     return push!(vi, vn, r, dist)
 end
 
@@ -1125,10 +1123,10 @@ end
 Push a new random variable `vn` with a sampled value `r` sampled with a sampler of
 selector `gid` from a distribution `dist` to `VarInfo` `vi`.
 """
-function push!(vi::AbstractVarInfo, vn::VarName, r, dist::Distribution, gid::Selector)
+function push!(vi::AbstractVarInfo, vn::VarName, r, dist, gid::Selector)
     return push!(vi, vn, r, dist, Set([gid]))
 end
-function push!(vi::VarInfo, vn::VarName, r, dist::Distribution, gidset::Set{Selector})
+function push!(vi::VarInfo, vn::VarName, r, dist, gidset::Set{Selector})
     if vi isa UntypedVarInfo
         @assert ~(vn in keys(vi)) "[push!] attempt to add an exisitng variable $(getsym(vn)) ($(vn)) to VarInfo (keys=$(keys(vi))) with dist=$dist, gid=$gidset"
     elseif vi isa TypedVarInfo