diff --git a/src/components/gradient_waveforms/changing_gradient_blocks.jl b/src/components/gradient_waveforms/changing_gradient_blocks.jl
index c3eb4cff744f4f000c6e203b29a4c0d813d64673..7c7a2a834063a91eb592c21ed4130dd98eca7e9a 100644
--- a/src/components/gradient_waveforms/changing_gradient_blocks.jl
+++ b/src/components/gradient_waveforms/changing_gradient_blocks.jl
@@ -14,6 +14,7 @@ Usually, you do not want to create this object directly, use a `BuildingBlock` i
 """
 abstract type ChangingGradient{N} <: GradientWaveform{N} end
 (::Type{ChangingGradient})(grad1::VariableType, slew_rate::VariableType, orientation::AbstractVector, duration::VariableType, group=nothing) = ChangingGradient1D(grad1, slew_rate, orientation, duration, group)
+(::Type{ChangingGradient})(grad1::AbstractVector, slew_rate::AbstractVector, ::Nothing, duration::VariableType, group=nothing) = ChangingGradient3D(grad1, slew_rate, duration, group)
 (::Type{ChangingGradient})(grad1::AbstractVector, slew_rate::AbstractVector, duration::VariableType, group=nothing) = ChangingGradient3D(grad1, slew_rate, duration, group)
 
 struct ChangingGradient1D <: ChangingGradient{1}
diff --git a/src/components/gradient_waveforms/constant_gradient_blocks.jl b/src/components/gradient_waveforms/constant_gradient_blocks.jl
index 7a545286a80d2aad3297b5386ca969348eb94df6..2004cb800b1a8a95d8bff240b290b5a1f5998849 100644
--- a/src/components/gradient_waveforms/constant_gradient_blocks.jl
+++ b/src/components/gradient_waveforms/constant_gradient_blocks.jl
@@ -13,7 +13,8 @@ Underlying type for any flat part in a 3D (first constructor) or 3D (second cons
 Usually, you do not want to create this object directly, use a `BuildingBlock` instead.
 """
 abstract type ConstantGradient{N} <: GradientWaveform{N} end
-(::Type{ConstantGradient})(grad1::VariableType, orientation::AbsractVector, duration::VariableType, group=nothing) = ConstantGradient1D(grad1, duration, orientation, group)
+(::Type{ConstantGradient})(grad1::VariableType, orientation::AbstractVector, duration::VariableType, group=nothing) = ConstantGradient1D(grad1, duration, orientation, group)
+(::Type{ConstantGradient})(grad1::AbstractVector, ::Nothing, duration::VariableType, group=nothing) = ConstantGradient3D(grad1, duration, group)
 (::Type{ConstantGradient})(grad1::AbstractVector, duration::VariableType, group=nothing) = ConstantGradient3D(grad1, duration, group)
 
 struct ConstantGradient1D <: ConstantGradient{1}