diff --git a/test/Integrators_I/step_limiter_test.jl b/test/Integrators_I/step_limiter_test.jl
index ea5a4c40e9..befe1f38ba 100644
--- a/test/Integrators_I/step_limiter_test.jl
+++ b/test/Integrators_I/step_limiter_test.jl
@@ -12,6 +12,13 @@ using OrdinaryDiffEqExtrapolation
 using OrdinaryDiffEqFIRK: AdaptiveRadau, RadauIIA9, RadauIIA5, RadauIIA3
 using LinearAlgebra
 
+@testset "Tests use local monorepo sources" begin
+    repo = normpath(joinpath(@__DIR__, "..", ".."))
+    @test pkgdir(OrdinaryDiffEqCore) == joinpath(repo, "lib", "OrdinaryDiffEqCore")
+    @test pkgdir(OrdinaryDiffEqLowOrderRK) == joinpath(repo, "lib", "OrdinaryDiffEqLowOrderRK")
+    @test pkgdir(OrdinaryDiffEqSSPRK) == joinpath(repo, "lib", "OrdinaryDiffEqSSPRK")
+end
+
 # define the counting variable
 const STEP_LIMITER_VAR = Ref(0)
 # define the step_limiter! function which just counts the number of step_limiter calls
diff --git a/test/runtests.jl b/test/runtests.jl
index 00fbfd92ca..61300ea33d 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -279,6 +279,9 @@ end
             Pkg.test(base_group, julia_args = ["--check-bounds=auto", "--compiled-modules=yes", "--depwarn=yes"], force_latest_compatible_version = false, allow_reresolve = true)
         end
     else
+        # Julia 1.10 does not resolve root [sources], so develop local sublibraries explicitly.
+        develop_sources!(dirname(@__DIR__))
+
         # Root-package group dispatch. `run_tests` owns the All / Interface /
         # Integrators / Regression / QA / functional-group routing that the old
         # hand-written `if GROUP == ...` ladder expressed. The group bodies