diff --git a/src/optimisation/Optimisation.jl b/src/optimisation/Optimisation.jl
index 9f1937ae4a..ffa94a3768 100644
--- a/src/optimisation/Optimisation.jl
+++ b/src/optimisation/Optimisation.jl
@@ -41,8 +41,8 @@ struct OptimizationContext{C<:AbstractContext} <: AbstractContext
     context::C
 
     function OptimizationContext{C}(context::C) where {C<:AbstractContext}
-        if !(context isa Union{DefaultContext,LikelihoodContext})
-            throw(ArgumentError("`OptimizationContext` supports only leaf contexts of type `DynamicPPL.DefaultContext` and `DynamicPPL.LikelihoodContext` (given: `$(typeof(context)))`"))
+        if !(context isa Union{DefaultContext,LikelihoodContext,PriorContext})
+            throw(ArgumentError("`OptimizationContext` supports only leaf contexts of type `DynamicPPL.DefaultContext`, `DynamicPPL.LikelihoodContext`, and `DynamicPPL.PriorContext` (given: `$(typeof(context)))`"))
         end
         return new{C}(context)
     end
@@ -55,7 +55,7 @@ DynamicPPL.NodeTrait(::OptimizationContext) = DynamicPPL.IsLeaf()
 # assume
 function DynamicPPL.tilde_assume(ctx::OptimizationContext, dist, vn, vi)
     r = vi[vn, dist]
-    lp = if ctx.context isa DefaultContext
+    lp = if (ctx.context isa DefaultContext) || (ctx.context isa PriorContext)
         # MAP
         Distributions.logpdf(dist, r)
     else
@@ -73,7 +73,7 @@ function DynamicPPL.dot_tilde_assume(ctx::OptimizationContext, right, left, vns,
     # affect anything.
     # TODO: Stop using `get_and_set_val!`.
     r = DynamicPPL.get_and_set_val!(Random.default_rng(), vi, vns, right, SampleFromPrior())
-    lp = if ctx.context isa DefaultContext
+    lp = if (ctx.context isa DefaultContext) || (ctx.context isa PriorContext)
         # MAP
         _loglikelihood(right, r)
     else
@@ -83,6 +83,12 @@ function DynamicPPL.dot_tilde_assume(ctx::OptimizationContext, right, left, vns,
     return r, lp, vi
 end
 
+DynamicPPL.tilde_observe(ctx::OptimizationContext{<:PriorContext}, args...) =
+    DynamicPPL.tilde_observe(ctx.context, args...)
+
+DynamicPPL.dot_tilde_observe(ctx::OptimizationContext{<:PriorContext}, args...) =
+    DynamicPPL.dot_tilde_observe(ctx.context, args...)
+
 """
     OptimLogDensity{M<:Model,C<:Context,V<:VarInfo}
 
diff --git a/test/optimisation/OptimInterface.jl b/test/optimisation/OptimInterface.jl
index 919de9702c..611d49a068 100644
--- a/test/optimisation/OptimInterface.jl
+++ b/test/optimisation/OptimInterface.jl
@@ -83,18 +83,18 @@ end
             mu = x*beta
             y ~ MvNormal(mu, I)
         end
-        
+
         Random.seed!(987)
         true_beta = [1.0, -2.2]
         x = rand(40, 2)
         y = x*true_beta
-        
+
         model = regtest(x, y)
         mle = optimize(model, MLE())
-        
+
         vcmat = inv(x'x)
         vcmat_mle = informationmatrix(mle).array
-        
+
         @test isapprox(mle.values.array, true_beta)
         @test isapprox(vcmat, vcmat_mle)
     end
@@ -103,10 +103,10 @@ end
         @model function dot_gdemo(x)
             s ~ InverseGamma(2,3)
             m ~ Normal(0, sqrt(s))
-        
+
             (.~)(x, Normal(m, sqrt(s)))
         end
-        
+
         model_dot = dot_gdemo([1.5, 2.0])
 
         mle1 = optimize(gdemo_default, MLE())
@@ -189,6 +189,22 @@ end
         x = 1.0
         w = [1.0]
 
+        @testset "Default, Likelihood, Prior Contexts" begin
+            m1 = model1(x)
+            defctx = Turing.OptimizationContext(DynamicPPL.DefaultContext())
+            llhctx = Turing.OptimizationContext(DynamicPPL.LikelihoodContext())
+            prictx = Turing.OptimizationContext(DynamicPPL.PriorContext())
+            a = [0.3]
+
+            @test Turing.OptimLogDensity(m1, defctx)(a) ==
+                Turing.OptimLogDensity(m1, llhctx)(a) +
+                Turing.OptimLogDensity(m1, prictx)(a)
+
+            # test that PriorContext is calculating the right thing
+            @test Turing.OptimLogDensity(m1, prictx)([0.3]) ≈ -Distributions.logpdf(Uniform(0, 2), 0.3)
+            @test Turing.OptimLogDensity(m1, prictx)([-0.3]) ≈ -Distributions.logpdf(Uniform(0, 2), -0.3)
+        end
+
         @testset "With ConditionContext" begin
             m1 = model1(x)
             m2 = model2() | (x = x,)