diff --git a/.github/workflows/CompatHelper.yml b/.github/workflows/CompatHelper.yml
index 68ca87ea5..c263a2b78 100644
--- a/.github/workflows/CompatHelper.yml
+++ b/.github/workflows/CompatHelper.yml
@@ -18,7 +18,7 @@ jobs:
       - name: "Run CompatHelper"
         run: |
           import CompatHelper
-          CompatHelper.main()
+          CompatHelper.main(; subdirs=["", "lib/ControlSystemsBase"])
         shell: julia --color=yes {0}
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/lib/ControlSystemsBase/Project.toml b/lib/ControlSystemsBase/Project.toml
index 4b3562a31..32557e8e6 100644
--- a/lib/ControlSystemsBase/Project.toml
+++ b/lib/ControlSystemsBase/Project.toml
@@ -31,7 +31,7 @@ ControlSystemsBaseImplicitDifferentiationExt = ["ImplicitDifferentiation", "Comp
 Aqua = "0.5"
 DSP = "0.6.1, 0.7, 0.8"
 ForwardDiff = "0.10"
-ImplicitDifferentiation = "0.4.2"
+ImplicitDifferentiation = "0.7.2"
 LinearAlgebra = "<0.0.1, 1"
 MacroTools = "0.5"
 MatrixEquations = "1, 2.1"
diff --git a/lib/ControlSystemsBase/ext/ControlSystemsBaseImplicitDifferentiationExt.jl b/lib/ControlSystemsBase/ext/ControlSystemsBaseImplicitDifferentiationExt.jl
index 229d909d1..f0ad7edd4 100644
--- a/lib/ControlSystemsBase/ext/ControlSystemsBaseImplicitDifferentiationExt.jl
+++ b/lib/ControlSystemsBase/ext/ControlSystemsBaseImplicitDifferentiationExt.jl
@@ -201,10 +201,12 @@ import ControlSystemsBase: hinfnorm
 function forward_hinfnorm(pars; kwargs...)
     (; A,B,C,D) = pars
     sys = ss(A,B,C,D)
-    hinfnorm(sys; kwargs...)
+    γ, w = hinfnorm(sys; kwargs...)
+    return [γ], w
 end
 
-function conditions_hinfnorm(pars, γ, w; tol=1e-10)
+function conditions_hinfnorm(pars, γ_vec, w; tol=1e-10)
+    γ = only(γ_vec)
     (; A,B,C,D) = pars
     sys = ss(A,B,C,D)
     [opnorm(freqresp(sys, w)) - γ]
@@ -222,8 +224,8 @@ A reverse-differentiation rule is defined in RobustAndOptimalControl.jl, which m
 function hinfnorm(sys::StateSpace{Continuous, <:Dual}; kwargs...)
     A,B,C,D = ssdata(sys)
     pars = ComponentVector(; A,B,C,D)
-    γ, w = implicit_hinfnorm(pars)
-    γ, w
+    γ_vec, w = implicit_hinfnorm(pars)
+    only(γ_vec), w
 end
 
 
@@ -264,4 +266,3 @@ end
 
 
 end # module
-