diff --git a/ext/DiffEqBaseGTPSAExt.jl b/ext/DiffEqBaseGTPSAExt.jl
index 65c383f73..10999bb26 100644
--- a/ext/DiffEqBaseGTPSAExt.jl
+++ b/ext/DiffEqBaseGTPSAExt.jl
@@ -1,14 +1,8 @@
 module DiffEqBaseGTPSAExt
 
-if isdefined(Base, :get_extension)
-    using DiffEqBase
-    import DiffEqBase: value, ODE_DEFAULT_NORM
-    using GTPSA
-else
-    using ..DiffEqBase
-    import ..DiffEqBase: value, ODE_DEFAULT_NORM
-    using ..GTPSA
-end
+using DiffEqBase
+import DiffEqBase: value, ODE_DEFAULT_NORM
+using GTPSA
 
 value(x::TPS) = scalar(x)
 value(::Type{<:TPS{T}}) where {T} = T
diff --git a/ext/DiffEqBaseGeneralizedGeneratedExt.jl b/ext/DiffEqBaseGeneralizedGeneratedExt.jl
index 44f478625..70a11e367 100644
--- a/ext/DiffEqBaseGeneralizedGeneratedExt.jl
+++ b/ext/DiffEqBaseGeneralizedGeneratedExt.jl
@@ -1,12 +1,7 @@
 module DiffEqBaseGeneralizedGeneratedExt
 
-if isdefined(Base, :get_extension)
-    using DiffEqBase
-    using GeneralizedGenerated
-else
-    using ..DiffEqBase
-    using ..GeneralizedGenerated
-end
+using DiffEqBase
+using GeneralizedGenerated
 
 function SciMLBase.numargs(::GeneralizedGenerated.RuntimeFn{Args}) where {Args}
     GeneralizedGenerated.from_type(Args) |> length
diff --git a/ext/DiffEqBaseMPIExt.jl b/ext/DiffEqBaseMPIExt.jl
index a5c0b2d82..f600079bb 100644
--- a/ext/DiffEqBaseMPIExt.jl
+++ b/ext/DiffEqBaseMPIExt.jl
@@ -1,12 +1,7 @@
 module DiffEqBaseMPIExt
 
-if isdefined(Base, :get_extension)
-    using DiffEqBase
-    import MPI
-else
-    using ..DiffEqBase
-    import ..MPI
-end
+using DiffEqBase
+import MPI
 
 if isdefined(MPI, :AbstractMultiRequest)
     function DiffEqBase.anyeltypedual(::Type{T},
diff --git a/ext/DiffEqBaseMeasurementsExt.jl b/ext/DiffEqBaseMeasurementsExt.jl
index 804cf0036..a72423708 100644
--- a/ext/DiffEqBaseMeasurementsExt.jl
+++ b/ext/DiffEqBaseMeasurementsExt.jl
@@ -1,14 +1,8 @@
 module DiffEqBaseMeasurementsExt
 
-if isdefined(Base, :get_extension)
-    using DiffEqBase
-    import DiffEqBase: value
-    using Measurements
-else
-    using ..DiffEqBase
-    import ..DiffEqBase: value
-    using ..Measurements
-end
+using DiffEqBase
+import DiffEqBase: value
+using Measurements
 
 function DiffEqBase.promote_u0(u0::AbstractArray{<:Measurements.Measurement},
         p::AbstractArray{<:Measurements.Measurement}, t0)
diff --git a/ext/DiffEqBaseMonteCarloMeasurementsExt.jl b/ext/DiffEqBaseMonteCarloMeasurementsExt.jl
index c00d479a8..d2b33d1a6 100644
--- a/ext/DiffEqBaseMonteCarloMeasurementsExt.jl
+++ b/ext/DiffEqBaseMonteCarloMeasurementsExt.jl
@@ -1,14 +1,8 @@
 module DiffEqBaseMonteCarloMeasurementsExt
 
-if isdefined(Base, :get_extension)
-    using DiffEqBase
-    import DiffEqBase: value
-    using MonteCarloMeasurements
-else
-    using ..DiffEqBase
-    import ..DiffEqBase: value
-    using ..MonteCarloMeasurements
-end
+using DiffEqBase
+import DiffEqBase: value
+using MonteCarloMeasurements
 
 function DiffEqBase.promote_u0(
         u0::AbstractArray{
diff --git a/ext/DiffEqBaseTrackerExt.jl b/ext/DiffEqBaseTrackerExt.jl
index 6d77714ba..34d40a2a5 100644
--- a/ext/DiffEqBaseTrackerExt.jl
+++ b/ext/DiffEqBaseTrackerExt.jl
@@ -1,14 +1,8 @@
 module DiffEqBaseTrackerExt
 
-if isdefined(Base, :get_extension)
-    using DiffEqBase
-    import DiffEqBase: value
-    import Tracker
-else
-    using ..DiffEqBase
-    import ..DiffEqBase: value
-    import ..Tracker
-end
+using DiffEqBase
+import DiffEqBase: value
+import Tracker
 
 DiffEqBase.value(x::Type{Tracker.TrackedReal{T}}) where {T} = T
 DiffEqBase.value(x::Type{Tracker.TrackedArray{T, N, A}}) where {T, N, A} = Array{T, N}
diff --git a/ext/DiffEqBaseUnitfulExt.jl b/ext/DiffEqBaseUnitfulExt.jl
index f17c63f65..381b0e516 100644
--- a/ext/DiffEqBaseUnitfulExt.jl
+++ b/ext/DiffEqBaseUnitfulExt.jl
@@ -1,14 +1,9 @@
 module DiffEqBaseUnitfulExt
 
-if isdefined(Base, :get_extension)
-    using DiffEqBase
-    import DiffEqBase: value
-    using Unitful
-else
-    using ..DiffEqBase
-    import ..DiffEqBase: value
-    using ..Unitful
-end
+using DiffEqBase
+import DiffEqBase: value
+using Unitful
+
 # Support adaptive errors should be errorless for exponentiation
 value(x::Type{Unitful.AbstractQuantity{T, D, U}}) where {T, D, U} = T
 value(x::Unitful.AbstractQuantity) = x.val