diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7f39463873..1aaac21ee3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@ Pkg v1.12 Release Notes
   The functions `Pkg.status`, `Pkg.why`, `Pkg.instantiate`, `Pkg.precompile` (and their REPL variants) have been updated
   to take a `workspace` option. Read more about this feature in the manual about the TOML-files.
 - `status` now shows when different versions/sources of dependencies are loaded than that which is expected by the manifest ([#4109])
+- It is now possible to specify "sources" for packages in a `[sources]` section in Project.toml.
+  This can be used to add non-registered normal or test dependencies. Packages are also automatically added to `[sources]` when they are added by url or devved.
 
 Pkg v1.11 Release Notes
 =======================
@@ -22,7 +24,7 @@ Pkg v1.10 Release Notes
 =======================
 
 Pkg v1.9 Release Notes
-=======================
+======================
 
 - New functionality: `Pkg.why` and `pkg> why` to show why a package is inside the environment (shows all "paths" to a package starting at the direct dependencies).
 - When code coverage tracking is enabled for `Pkg.test` the new path-specific code-coverage option is used to limit coverage
diff --git a/src/API.jl b/src/API.jl
index 834fbdcef5..70a59334e3 100644
--- a/src/API.jl
+++ b/src/API.jl
@@ -190,15 +190,26 @@ end
 function update_source_if_set(project, pkg)
     source = get(project.sources, pkg.name, nothing)
     source === nothing && return
-    # This should probably not modify the dicts directly...
-    if pkg.repo.source !== nothing
-        source["url"] = pkg.repo.source
-    end
-    if pkg.repo.rev !== nothing
-        source["rev"] = pkg.repo.rev
-    end
-    if pkg.path !== nothing
-        source["path"] = pkg.path
+    if pkg.repo == GitRepo()
+        delete!(project.sources, pkg.name)
+    else
+        # This should probably not modify the dicts directly...
+        if pkg.repo.source !== nothing
+            source["url"] = pkg.repo.source
+            delete!(source, "path")
+        end
+        if pkg.repo.rev !== nothing
+            source["rev"] = pkg.repo.rev
+            delete!(source, "path")
+        end
+        if pkg.repo.subdir !== nothing
+            source["subdir"] = pkg.repo.subdir
+        end
+        if pkg.path !== nothing
+            source["path"] = pkg.path
+            delete!(source, "url")
+            delete!(source, "rev")
+        end
     end
     if pkg.subdir !== nothing
         source["subdir"] = pkg.subdir
@@ -427,6 +438,7 @@ function pin(ctx::Context, pkgs::Vector{PackageSpec}; all_pkgs::Bool=false, kwar
                 pkgerror("pinning a package requires a single version, not a versionrange")
             end
         end
+        update_source_if_set(ctx.env.project, pkg)
     end
 
     project_deps_resolve!(ctx.env, pkgs)
diff --git a/src/Types.jl b/src/Types.jl
index 5f72f49c96..96f951434f 100644
--- a/src/Types.jl
+++ b/src/Types.jl
@@ -1230,6 +1230,14 @@ function write_env(env::EnvCache; update_undo=true,
                 @assert entry.repo.subdir == repo.subdir
             end
         end
+        if entry.path !== nothing
+            env.project.sources[pkg] = Dict("path" => entry.path)
+        elseif entry.repo != GitRepo()
+            d = Dict("url" => entry.repo.source)
+            entry.repo.rev !== nothing && (d["rev"] = entry.repo.rev)
+            entry.repo.subdir !== nothing && (d["subdir"] = entry.repo.subdir)
+            env.project.sources[pkg] = d
+        end
     end
 
     if (env.project != env.original_project) && (!skip_writing_project)
diff --git a/test/new.jl b/test/new.jl
index 4f68bca11d..8b4f4c3bc1 100644
--- a/test/new.jl
+++ b/test/new.jl
@@ -3248,16 +3248,18 @@ temp_pkg_dir() do project_path
     end
 end
 @testset "test resolve with tree hash" begin
-    mktempdir() do dir
-        path = copy_test_package(dir, "ResolveWithRev")
-        cd(path) do
-            with_current_env() do
-                @test !isfile("Manifest.toml")
-                @test !isdir(joinpath(DEPOT_PATH[1], "packages", "Example"))
-                Pkg.resolve()
-                @test isdir(joinpath(DEPOT_PATH[1], "packages", "Example"))
-                rm(joinpath(DEPOT_PATH[1], "packages", "Example"); recursive = true)
-                Pkg.resolve()
+    isolate() do
+        mktempdir() do dir
+            path = copy_test_package(dir, "ResolveWithRev")
+            cd(path) do
+                with_current_env() do
+                    @test !isfile("Manifest.toml")
+                    @test !isdir(joinpath(DEPOT_PATH[1], "packages", "Example"))
+                    Pkg.resolve()
+                    @test isdir(joinpath(DEPOT_PATH[1], "packages", "Example"))
+                    rm(joinpath(DEPOT_PATH[1], "packages", "Example"); recursive=true)
+                    Pkg.resolve()
+                end
             end
         end
     end
diff --git a/test/sources.jl b/test/sources.jl
index 35425aea21..aeb42313e0 100644
--- a/test/sources.jl
+++ b/test/sources.jl
@@ -21,7 +21,7 @@ temp_pkg_dir() do project_path
                     cp("Project.toml.bak", "Project.toml"; force=true)
                     cp("BadManifest.toml", "Manifest.toml"; force=true)
                     Pkg.resolve()
-                    @test Pkg.project().sources["Example"] == Dict("url" => "https://github.com/JuliaLang/Example.jl")
+                    @test Pkg.project().sources["Example"] == Dict("rev" => "master", "url" => "https://github.com/JuliaLang/Example.jl")
                     @test Pkg.project().sources["LocalPkg"] == Dict("path" => "LocalPkg")
                 end
             end