diff --git a/apps/debugger/lib/debugger/server.ex b/apps/debugger/lib/debugger/server.ex
index b492be88..3b59efd5 100644
--- a/apps/debugger/lib/debugger/server.ex
+++ b/apps/debugger/lib/debugger/server.ex
@@ -443,7 +443,7 @@ defmodule ElixirLS.Debugger.Server do
 
     # FIXME: Private API
     unless match?(%{file: ^mixfile}, Mix.ProjectStack.peek()) do
-      Code.require_file(System.get_env("MIX_EXS") || "mix.exs")
+      Code.compile_file(System.get_env("MIX_EXS") || "mix.exs")
     end
 
     task = task || Mix.Project.config()[:default_task]
@@ -555,7 +555,10 @@ defmodule ElixirLS.Debugger.Server do
       %{name: name, file: file} = project
       :code.purge(name)
       :code.delete(name)
-      Code.require_file(file)
+      # It's important to use `compile_file` here instead of `require_file`
+      # because we are recompiling this file to reload the mix project back onto
+      # the project stack.
+      Code.compile_file(file)
     end
   end
 
diff --git a/apps/elixir_ls_utils/test/support/mix_test.case.ex b/apps/elixir_ls_utils/test/support/mix_test.case.ex
index 9f7905bb..2d23c6e7 100644
--- a/apps/elixir_ls_utils/test/support/mix_test.case.ex
+++ b/apps/elixir_ls_utils/test/support/mix_test.case.ex
@@ -129,7 +129,10 @@ defmodule ElixirLS.Utils.MixTest.Case do
     for %{name: module, file: file} <- stack do
       :code.purge(module)
       :code.delete(module)
-      Code.require_file(file)
+      # It's important to use `compile_file` here instead of `require_file`
+      # because we are recompiling this file to reload the mix project back onto
+      # the project stack.
+      Code.compile_file(file)
     end
   end