diff --git a/src/concrete_solve.jl b/src/concrete_solve.jl
index 22a45664c..bfd6f09eb 100644
--- a/src/concrete_solve.jl
+++ b/src/concrete_solve.jl
@@ -40,10 +40,18 @@ function inplace_vjp(prob, u0, p, verbose)
 
     vjp = try
         f = unwrapped_f(prob.f)
-        ReverseDiff.GradientTape((copy(u0), p, [prob.tspan[1]])) do u, p, t
-            du1 = similar(u, size(u))
-            f(du1, u, p, first(t))
-            return vec(du1)
+        if p === nothing || p isa SciMLBase.NullParameters
+            ReverseDiff.GradientTape((copy(u0), [prob.tspan[1]])) do u, t
+                du1 = similar(u, size(u))
+                f(du1, u, p, first(t))
+                return vec(du1)
+            end
+        else
+            ReverseDiff.GradientTape((copy(u0), p, [prob.tspan[1]])) do u, p, t
+                du1 = similar(u, size(u))
+                f(du1, u, p, first(t))
+                return vec(du1)
+            end
         end
         ReverseDiffVJP(compile)
     catch e
@@ -73,7 +81,11 @@ function automatic_sensealg_choice(prob::Union{SciMLBase.AbstractODEProblem,
         # so if out-of-place, try Zygote
 
         vjp = try
-            Zygote.gradient((u, p) -> sum(prob.f(u, p, prob.tspan[1])), u0, p)
+            if p === nothing || p isa SciMLBase.NullParameters
+                Zygote.gradient((u) -> sum(prob.f(u, p, prob.tspan[1])), u0)
+            else
+                Zygote.gradient((u, p) -> sum(prob.f(u, p, prob.tspan[1])), u0, p)
+            end
             ZygoteVJP()
         catch e
             if verbose
@@ -86,7 +98,11 @@ function automatic_sensealg_choice(prob::Union{SciMLBase.AbstractODEProblem,
 
         if vjp == false
             vjp = try
-                ReverseDiff.gradient((u, p) -> sum(prob.f(u, p, prob.tspan[1])), u0, p)
+                if p === nothing || p isa SciMLBase.NullParameters
+                    ReverseDiff.gradient((u) -> sum(prob.f(u, p, prob.tspan[1])), u0)
+                else
+                    ReverseDiff.gradient((u, p) -> sum(prob.f(u, p, prob.tspan[1])), u0, p)
+                end
                 ReverseDiffVJP()
             catch e
                 if verbose
@@ -100,7 +116,11 @@ function automatic_sensealg_choice(prob::Union{SciMLBase.AbstractODEProblem,
 
         if vjp == false
             vjp = try
-                Tracker.gradient((u, p) -> sum(prob.f(u, p, prob.tspan[1])), u0, p)
+                if p === nothing || p isa SciMLBase.NullParameters
+                    Tracker.gradient((u) -> sum(prob.f(u, p, prob.tspan[1])), u0)
+                else
+                    Tracker.gradient((u, p) -> sum(prob.f(u, p, prob.tspan[1])), u0, p)
+                end
                 TrackerVJP()
             catch e
                 if verbose