diff --git a/Project.toml b/Project.toml
index 07c83db..c641555 100644
--- a/Project.toml
+++ b/Project.toml
@@ -13,7 +13,7 @@ SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 
 [compat]
 Catalyst = "15"
-DiffEqBase = "6, 7"
+DiffEqBase = "6.165, 7"
 Distributions = "0.25"
 LinearAlgebra = "1"
 MacroTools = "^0.5.5"
diff --git a/src/build_rhs.jl b/src/build_rhs.jl
index 2332580..2b8254c 100644
--- a/src/build_rhs.jl
+++ b/src/build_rhs.jl
@@ -140,6 +140,6 @@ Return an `ODEProblem` for use in `DifferentialEquations`. This function implici
 calls `convert(ODEFunction, sys)`. It is usually more efficient to create an `ODEFunction`
 first and then use that to create `ODEProblem`s.
 """
-function DiffEqBase.ODEProblem(sys::FSPSystem, u0, tint, pmap = NullParameters())
+function DiffEqBase.ODEProblem(sys::FSPSystem, u0, tint, pmap = DiffEqBase.NullParameters())
     return ODEProblem(convert(ODEFunction, sys), u0, tint, pmap_to_p(sys, pmap))
 end
diff --git a/src/build_rhs_ss.jl b/src/build_rhs_ss.jl
index ba2c2dd..c44cf59 100644
--- a/src/build_rhs_ss.jl
+++ b/src/build_rhs_ss.jl
@@ -75,6 +75,6 @@ end
 
 Return a `SteadyStateProblem` for use in `DifferentialEquations.
 """
-function DiffEqBase.SteadyStateProblem(sys::FSPSystem, u0, pmap = NullParameters())
+function DiffEqBase.SteadyStateProblem(sys::FSPSystem, u0, pmap = DiffEqBase.NullParameters())
     return SteadyStateProblem(convert(ODEFunction, sys, SteadyState()), u0, pmap_to_p(sys, pmap))
 end