diff --git a/src/scimlfunctions.jl b/src/scimlfunctions.jl
index 5c4ec2d04..2dc18cab2 100644
--- a/src/scimlfunctions.jl
+++ b/src/scimlfunctions.jl
@@ -4279,7 +4279,6 @@ function OptimizationFunction{iip}(f, adtype::AbstractADType = NoAD();
         lag_hess_colorvec = nothing,
         initialization_data = __has_initialization_data(f) ? f.initialization_data :
                               nothing) where {iip}
-    isinplace(f, 2; has_two_dispatches = false, isoptimization = true)
     sys = sys_or_symbolcache(sys, syms, paramsyms)
     OptimizationFunction{
         iip, typeof(adtype), typeof(f), typeof(grad), typeof(fg), typeof(hess),
diff --git a/test/function_building_error_messages.jl b/test/function_building_error_messages.jl
index f07c9fc62..8031ef697 100644
--- a/test/function_building_error_messages.jl
+++ b/test/function_building_error_messages.jl
@@ -507,6 +507,14 @@ optf(u, p) = 1.0
 OptimizationFunction(optf)
 OptimizationProblem(optf, 1.0)
 
+# Test OptimizationFunction{iip} respects explicit iip parameter
+# This function would fail isinplace check due to method ambiguity
+struct ProblematicOptFunction end
+(::ProblematicOptFunction)(x, p) = sum(x .^ 2)
+# But when iip is explicitly provided, it should work without calling isinplace
+@test_nowarn OptimizationFunction{false}(ProblematicOptFunction())
+@test_nowarn OptimizationFunction{true}(ProblematicOptFunction())
+
 # BVPFunction
 
 bfoop(u, p, t) = u