diff --git a/.ci/run_tests.jl b/.ci/run_tests.jl
index 8a54ef62..879b73b1 100644
--- a/.ci/run_tests.jl
+++ b/.ci/run_tests.jl
@@ -6,6 +6,5 @@ end
 
 proj = abspath(joinpath(@__DIR__, ".."))
 cmd = """Base.runtests(["LinearAlgebra"]; propagate_project=true, ncores=$ncores)"""
-withenv("JULIA_NUM_THREADS" => 1) do
-    run(`$(Base.julia_cmd()) --project=$proj --compiled-modules=existing -e $cmd`)
-end
+run(addenv(`$(Base.julia_cmd()) --project=$proj --compiled-modules=existing -e $cmd`,
+    "JULIA_NUM_THREADS" => 1, "JULIA_PRUNE_OLD_LA" => true))
diff --git a/README.md b/README.md
index a39a7248..c0951dcc 100644
--- a/README.md
+++ b/README.md
@@ -37,10 +37,37 @@ This package performs some type piracy and is also included in the sysimage, whi
 To use a development version of this package, you can choose one of the following methods:
 
 1. **Change the UUID in the project file and load the package:**
-   This approach will produce warnings and may lead to method ambiguities between the development version and the one in the sysimage, but it can be used for basic experimentation.
+
+   Change the UUID line in `Project.toml` as
+   ```diff
+   - uuid = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+   + uuid = "27e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+   ```
+
+   Start `julia` as
+   ```console
+   JULIA_PRUNE_OLD_LA=true julia +nightly --compiled-modules=existing --project
+   ```
+   where it is assumed that one is already within the `LinearAlgebra` directory (otherwise, adjust
+   the project path accordingly). The `julia +nightly` command above assumes that `juliaup` is being used
+   to launch `julia`, but one may substitute this with the path to the julia executable.
+
+   Within the `julia` session, load the `LinearAlgebra` module after pruning the one in the sysimage. This may be done as
+   ```julia
+   include("test/prune_old_LA.jl") && using LinearAlgebra
+   ```
+
+   Note that loading the test files in the REPL will automatically carry out the pruning to ensure that the development version of the package is used in the tests.
+
+   If you are contributing to the repo using this method, it may be convenient to ignore the local changes to `Project.toml` by running
+   ```console
+   git update-index --skip-worktree Project.toml
+   ```
 
 2. **Build Julia with the custom `LinearAlgebra` commit:**
-   Modify the commit in `stdlib/LinearAlgebra.version` and build Julia.
+
+   Modify the commit in [`stdlib/LinearAlgebra.version`](https://github.com/JuliaLang/julia/blob/master/stdlib/LinearAlgebra.version) and build Julia. This requires one to push the development branch
+   to `GitHub` or an equivalent platform.
 
 3. **Build a custom sysimage with the new `LinearAlgebra`:**
    - Install `PackageCompiler`.
diff --git a/docs/make.jl b/docs/make.jl
index a1d3a2d0..0f8b79d9 100644
--- a/docs/make.jl
+++ b/docs/make.jl
@@ -1,4 +1,6 @@
-include("../test/prune_old_LA.jl")
+withenv("JULIA_PRUNE_OLD_LA" => "true") do
+    include("../test/prune_old_LA.jl")
+end
 
 using LinearAlgebra
 using Documenter: DocMeta, makedocs, deploydocs, HTML
diff --git a/test/bitarray.jl b/test/bitarray.jl
index a185873e..10b9d4b8 100644
--- a/test/bitarray.jl
+++ b/test/bitarray.jl
@@ -1,3 +1,7 @@
+# This file is a part of Julia. License is MIT: https://julialang.org/license
+
+module TestBitArray
+
 isdefined(Main, :pruned_old_LA) || @eval Main include("prune_old_LA.jl")
 
 using LinearAlgebra, Test, Random
@@ -95,3 +99,5 @@ b2 = bitrand(v1)
 
 b1 = bitrand(n1, n1)
 @check_bit_operation diag(b1)
+
+end # module
diff --git a/test/prune_old_LA.jl b/test/prune_old_LA.jl
index f628cddf..7e64cfa3 100644
--- a/test/prune_old_LA.jl
+++ b/test/prune_old_LA.jl
@@ -1,56 +1,58 @@
-methods_to_delete =
-[
-:adjoint
-:transpose
-:inv
-:literal_pow
-:\
-:/
-:isapprox
-:copyto!
-:*
-:muladd
-:copyto!
-:isone
-:kron!
-:kron
-:^
-:exp
-:cis
-:log
-:sqrt
-:cbrt
-:inv
-:cos
-:sin
-:sincos
-:tan
-:cosh
-:sinh
-:tanh
-:acos
-:asin
-:atan
-:acosh
-:asinh
-:atanh
-:sec
-:sech
-:csc
-:csch
-:cot
-:coth
-:asec
-:asech
-:acsc
-:acot
-:acoth
-:acsch
-]
-
 let
-    LA = get(Base.loaded_modules, Base.PkgId(Base.UUID("37e2e46d-f89d-539d-b4ee-838fcccc9c8e"), "LinearAlgebra"), nothing)
-    if LA !== nothing
+    methods_to_delete =
+    [
+    :adjoint
+    :transpose
+    :inv
+    :literal_pow
+    :\
+    :/
+    :isapprox
+    :copyto!
+    :*
+    :muladd
+    :copyto!
+    :isone
+    :kron!
+    :kron
+    :^
+    :exp
+    :cis
+    :log
+    :sqrt
+    :cbrt
+    :inv
+    :cos
+    :sin
+    :sincos
+    :tan
+    :cosh
+    :sinh
+    :tanh
+    :acos
+    :asin
+    :atan
+    :acosh
+    :asinh
+    :atanh
+    :sec
+    :sech
+    :csc
+    :csch
+    :cot
+    :coth
+    :asec
+    :asech
+    :acsc
+    :acot
+    :acoth
+    :acsch
+    ]
+
+    prune_old_LA = parse(Bool, get(ENV, "JULIA_PRUNE_OLD_LA", "false"))
+    LinalgSysImg = Base.PkgId(Base.UUID("37e2e46d-f89d-539d-b4ee-838fcccc9c8e"), "LinearAlgebra")
+    LA = get(Base.loaded_modules, LinalgSysImg, nothing)
+    if LA !== nothing && prune_old_LA
         @assert hasmethod(*, Tuple{Matrix{Float64}, Matrix{Float64}})
         for methss in methods_to_delete
             meths = getglobal(Base, methss)
@@ -61,9 +63,17 @@ let
             end
         end
     end
-    Base.unreference_module(Base.PkgId(Base.UUID("37e2e46d-f89d-539d-b4ee-838fcccc9c8e"), "LinearAlgebra"))
 end
 
-@assert !hasmethod(*, Tuple{Matrix{Float64}, Matrix{Float64}})
+# check in a separate block to ensure that the latest world age is used
+let
+    prune_old_LA = parse(Bool, get(ENV, "JULIA_PRUNE_OLD_LA", "false"))
+    LinalgSysImg = Base.PkgId(Base.UUID("37e2e46d-f89d-539d-b4ee-838fcccc9c8e"), "LinearAlgebra")
+    LA = get(Base.loaded_modules, LinalgSysImg, nothing)
+    if LA !== nothing && prune_old_LA
+        @assert !hasmethod(*, Tuple{Matrix{Float64}, Matrix{Float64}})
+    end
+    prune_old_LA && Base.unreference_module(LinalgSysImg)
+end
 
 pruned_old_LA = true