diff --git a/lib/eex/lib/eex/engine.ex b/lib/eex/lib/eex/engine.ex
index 12234f048c8..f17c211cb3b 100644
--- a/lib/eex/lib/eex/engine.ex
+++ b/lib/eex/lib/eex/engine.ex
@@ -195,7 +195,7 @@ defmodule EEx.Engine do
   def handle_expr(state, "=", ast) do
     check_state!(state)
     %{binary: binary, dynamic: dynamic, vars_count: vars_count} = state
-    var = Macro.var(:"arg#{vars_count}", __MODULE__)
+    var = Macro.var(String.to_unsafe_atom("arg#{vars_count}"), __MODULE__)
 
     ast =
       quote do
diff --git a/lib/elixir/lib/base.ex b/lib/elixir/lib/base.ex
index 35016ab7e4a..4847a12238c 100644
--- a/lib/elixir/lib/base.ex
+++ b/lib/elixir/lib/base.ex
@@ -436,7 +436,7 @@ defmodule Base do
   end
 
   for {base, alphabet} <- [upper: b16_alphabet, lower: to_lower_enc.(b16_alphabet)] do
-    name = :"encode16#{base}"
+    name = String.to_unsafe_atom("encode16#{base}")
     encoded = to_encode_list.(alphabet)
 
     @compile {:inline, [{name, 1}]}
@@ -617,10 +617,10 @@ defmodule Base do
   upper = Enum.with_index(b16_alphabet)
 
   for {base, alphabet} <- [upper: upper, lower: to_lower_dec.(upper), mixed: to_mixed_dec.(upper)] do
-    decode_name = :"decode16#{base}!"
-    validate_name = :"validate16#{base}?"
-    valid_char_name = :"valid_char16#{base}?"
-    valid_word_name = :"valid_word16#{base}?"
+    decode_name = String.to_unsafe_atom("decode16#{base}!")
+    validate_name = String.to_unsafe_atom("validate16#{base}?")
+    valid_char_name = String.to_unsafe_atom("valid_char16#{base}?")
+    valid_word_name = String.to_unsafe_atom("valid_word16#{base}?")
 
     {min, decoded} = to_decode_list.(alphabet)
 
@@ -735,7 +735,7 @@ defmodule Base do
   end
 
   for {base, alphabet} <- [base: b64_alphabet, url: b64url_alphabet] do
-    name = :"encode64#{base}"
+    name = String.to_unsafe_atom("encode64#{base}")
     encoded = to_encode_list.(alphabet)
 
     @compile {:inline, [{name, 1}]}
@@ -1001,12 +1001,12 @@ defmodule Base do
   end
 
   for {base, alphabet} <- [base: b64_alphabet, url: b64url_alphabet] do
-    decode_name = :"decode64#{base}!"
+    decode_name = String.to_unsafe_atom("decode64#{base}!")
 
-    validate_name = :"validate64#{base}?"
-    validate_main_name = :"validate_main64#{validate_name}?"
-    valid_char_name = :"valid_char64#{base}?"
-    valid_word_name = :"valid_word64#{base}?"
+    validate_name = String.to_unsafe_atom("validate64#{base}?")
+    validate_main_name = String.to_unsafe_atom("validate_main64#{validate_name}?")
+    valid_char_name = String.to_unsafe_atom("valid_char64#{base}?")
+    valid_word_name = String.to_unsafe_atom("valid_word64#{base}?")
     {min, decoded} = alphabet |> Enum.with_index() |> to_decode_list.()
 
     # SWAR fast path: 7 bytes per stride, validated via `valid_word64<base>?`
@@ -1314,7 +1314,7 @@ defmodule Base do
         hexupper: b32hex_alphabet,
         hexlower: to_lower_enc.(b32hex_alphabet)
       ] do
-    name = :"encode32#{base}"
+    name = String.to_unsafe_atom("encode32#{base}")
     encoded = to_encode_list.(alphabet)
 
     @compile {:inline, [{name, 1}]}
@@ -1653,16 +1653,16 @@ defmodule Base do
         hexlower: to_lower_dec.(hexupper),
         hexmixed: to_mixed_dec.(hexupper)
       ] do
-    decode_name = :"decode32#{base}!"
-    validate_name = :"validate32#{base}?"
-    validate_main_name = :"validate_main32#{validate_name}?"
-    valid_char_name = :"valid_char32#{base}?"
+    decode_name = String.to_unsafe_atom("decode32#{base}!")
+    validate_name = String.to_unsafe_atom("validate32#{base}?")
+    validate_main_name = String.to_unsafe_atom("validate_main32#{validate_name}?")
+    valid_char_name = String.to_unsafe_atom("valid_char32#{base}?")
     {min, decoded} = to_decode_list.(alphabet)
 
     # SWAR fast path: 7 bytes per stride, validated via `valid_word32<base>?`
     # in the body. Tail leftover (1-6 bytes after a 7-byte stride hits an
     # 8-byte-multiple `main`) recurses through the single-byte clause.
-    valid_word_name = :"valid_word32#{base}?"
+    valid_word_name = String.to_unsafe_atom("valid_word32#{base}?")
 
     defp unquote(validate_main_name)(<<w::56, rest::binary>>),
       do: unquote(valid_word_name)(w) and unquote(validate_main_name)(rest)
diff --git a/lib/elixir/lib/code.ex b/lib/elixir/lib/code.ex
index 97c5931c88d..bca3c20cf20 100644
--- a/lib/elixir/lib/code.ex
+++ b/lib/elixir/lib/code.ex
@@ -767,6 +767,12 @@ defmodule Code do
     * `:migrate` (since v1.18.0) - when `true`, sets all other migration options
       to `true` by default. Defaults to `false`.
 
+    * `:migrate_atom_interpolations` (since v1.21.0) - when `true`, rewrites
+      deprecated atom interpolations to explicit calls to `String.to_unsafe_atom/1`.
+      For example, `:"foo_#{bar}"` becomes `String.to_unsafe_atom("foo_#{bar}")`
+      and `["foo_#{bar}": 1]` becomes `[{String.to_unsafe_atom("foo_#{bar}"), 1}]`.
+      Defaults to the value of the `:migrate` option. This option changes the AST.
+
     * `:migrate_bitstring_modifiers` (since v1.18.0) - when `true`,
       removes unnecessary parentheses in known bitstring
       [modifiers](`<<>>/1`), for example `<<foo::binary()>>`
diff --git a/lib/elixir/lib/code/formatter.ex b/lib/elixir/lib/code/formatter.ex
index b6320d199db..11dc9675fe4 100644
--- a/lib/elixir/lib/code/formatter.ex
+++ b/lib/elixir/lib/code/formatter.ex
@@ -195,6 +195,7 @@ defmodule Code.Formatter do
     file = Keyword.get(opts, :file, nil)
     sigils = Keyword.get(opts, :sigils, [])
     migrate = Keyword.get(opts, :migrate, false)
+    migrate_atom_interpolations = Keyword.get(opts, :migrate_atom_interpolations, migrate)
     migrate_bitstring_modifiers = Keyword.get(opts, :migrate_bitstring_modifiers, migrate)
     migrate_call_parens_on_pipe = Keyword.get(opts, :migrate_call_parens_on_pipe, migrate)
     migrate_charlists_as_sigils = Keyword.get(opts, :migrate_charlists_as_sigils, migrate)
@@ -223,6 +224,7 @@ defmodule Code.Formatter do
       comments: comments,
       sigils: sigils,
       file: file,
+      migrate_atom_interpolations: migrate_atom_interpolations,
       migrate_bitstring_modifiers: migrate_bitstring_modifiers,
       migrate_call_parens_on_pipe: migrate_call_parens_on_pipe,
       migrate_charlists_as_sigils: migrate_charlists_as_sigils,
@@ -334,14 +336,20 @@ defmodule Code.Formatter do
   end
 
   defp quoted_to_algebra(
-         {{:., _, [:erlang, :binary_to_atom]}, _, [{:<<>>, _, entries}, :utf8]} = quoted,
+         {{:., _, [:erlang, :binary_to_atom]}, _, [{:<<>>, _, entries} = bitstring, :utf8]} =
+           quoted,
          context,
          state
        ) do
-    if interpolated?(entries) do
-      interpolation_to_algebra(entries, @double_quote, state, ":\"", @double_quote)
-    else
-      remote_to_algebra(quoted, context, state)
+    cond do
+      not interpolated?(entries) ->
+        remote_to_algebra(quoted, context, state)
+
+      state.migrate_atom_interpolations ->
+        quoted_to_algebra(quote(do: String.to_unsafe_atom(unquote(bitstring))), context, state)
+
+      true ->
+        interpolation_to_algebra(entries, @double_quote, state, ":\"", @double_quote)
     end
   end
 
diff --git a/lib/elixir/lib/io/ansi.ex b/lib/elixir/lib/io/ansi.ex
index d8e49d0a95b..b12ea3e3e36 100644
--- a/lib/elixir/lib/io/ansi.ex
+++ b/lib/elixir/lib/io/ansi.ex
@@ -159,7 +159,7 @@ defmodule IO.ANSI do
 
   for font_n <- [1, 2, 3, 4, 5, 6, 7, 8, 9] do
     @doc "Sets alternative font #{font_n}."
-    defsequence.(:"font_#{font_n}", font_n + 10, "m")
+    defsequence.(String.to_unsafe_atom("font_#{font_n}"), font_n + 10, "m")
   end
 
   @doc "Normal color or intensity."
@@ -193,13 +193,13 @@ defmodule IO.ANSI do
     defsequence.(color, code + 30, "m")
 
     @doc "Sets foreground color to light #{color}."
-    defsequence.(:"light_#{color}", code + 90, "m")
+    defsequence.(String.to_unsafe_atom("light_#{color}"), code + 90, "m")
 
     @doc "Sets background color to #{color}."
-    defsequence.(:"#{color}_background", code + 40, "m")
+    defsequence.(String.to_unsafe_atom("#{color}_background"), code + 40, "m")
 
     @doc "Sets background color to light #{color}."
-    defsequence.(:"light_#{color}_background", code + 100, "m")
+    defsequence.(String.to_unsafe_atom("light_#{color}_background"), code + 100, "m")
   end
 
   @doc "Default text color."
diff --git a/lib/elixir/lib/macro/env.ex b/lib/elixir/lib/macro/env.ex
index 5ec87336e7d..a7651dd460b 100644
--- a/lib/elixir/lib/macro/env.ex
+++ b/lib/elixir/lib/macro/env.ex
@@ -213,13 +213,13 @@ defmodule Macro.Env do
   @doc false
   @deprecated "Use Macro.Env.expand_alias/4 instead"
   def fetch_alias(%{__struct__: Macro.Env, aliases: aliases}, atom) when is_atom(atom),
-    do: Keyword.fetch(aliases, :"Elixir.#{atom}")
+    do: Keyword.fetch(aliases, String.to_unsafe_atom("Elixir.#{atom}"))
 
   @doc false
   @deprecated "Use Macro.Env.expand_alias/4 instead"
   def fetch_macro_alias(%{__struct__: Macro.Env, macro_aliases: aliases}, atom)
       when is_atom(atom),
-      do: Keyword.fetch(aliases, :"Elixir.#{atom}")
+      do: Keyword.fetch(aliases, String.to_unsafe_atom("Elixir.#{atom}"))
 
   @doc """
   Returns the modules from which the given `{name, arity}` was
diff --git a/lib/elixir/lib/module.ex b/lib/elixir/lib/module.ex
index 6af24400741..e7c9f37d028 100644
--- a/lib/elixir/lib/module.ex
+++ b/lib/elixir/lib/module.ex
@@ -1192,7 +1192,7 @@ defmodule Module do
   defp expand_key(key, counters) do
     case counters do
       %{^key => count} when is_integer(count) and count >= 1 ->
-        {{:"#{key}#{count}", [], Elixir}, Map.put(counters, key, count - 1)}
+        {{String.to_unsafe_atom("#{key}#{count}"), [], Elixir}, Map.put(counters, key, count - 1)}
 
       _ ->
         {{key, [], Elixir}, counters}
@@ -1225,7 +1225,8 @@ defmodule Module do
   defp merge_signature({var, _, _} = older, {var, _, _}, _), do: older
 
   # Otherwise, returns a generic guess
-  defp merge_signature({_, meta, _}, _newer, i), do: {:"arg#{i}", meta, Elixir}
+  defp merge_signature({_, meta, _}, _newer, i),
+    do: {String.to_unsafe_atom("arg#{i}"), meta, Elixir}
 
   @doc """
   Checks if the module defines the given function or macro.
diff --git a/lib/elixir/test/elixir/file/stream_test.exs b/lib/elixir/test/elixir/file/stream_test.exs
index 98df2313515..ecfef55ee21 100644
--- a/lib/elixir/test/elixir/file/stream_test.exs
+++ b/lib/elixir/test/elixir/file/stream_test.exs
@@ -21,7 +21,8 @@ defmodule File.StreamTest do
     :erpc.call(node, File, :stream!, [src, modes, lines_or_bytes])
   end
 
-  distributed_node = :"secondary@#{node() |> Atom.to_string() |> :binary.split("@") |> tl()}"
+  distributed_node =
+    String.to_unsafe_atom("secondary@#{node() |> Atom.to_string() |> :binary.split("@") |> tl()}")
 
   for {type, node} <- [local: node(), distributed: distributed_node] do
     describe "#{type} node" do
diff --git a/lib/elixir/test/elixir/module/types/descr_test.exs b/lib/elixir/test/elixir/module/types/descr_test.exs
index a79b2aa956c..f1340e357fa 100644
--- a/lib/elixir/test/elixir/module/types/descr_test.exs
+++ b/lib/elixir/test/elixir/module/types/descr_test.exs
@@ -33,8 +33,8 @@ defmodule Module.Types.DescrTest do
       opt_difference(
         acc,
         open_map([
-          {:k, open_map([{:"value#{index}", integer()}])},
-          {:"field#{index}", integer()}
+          {:k, open_map([{String.to_unsafe_atom("value#{index}"), integer()}])},
+          {String.to_unsafe_atom("field#{index}"), integer()}
         ])
       )
     end)
@@ -45,7 +45,7 @@ defmodule Module.Types.DescrTest do
       opt_difference(
         acc,
         open_tuple([
-          open_tuple([atom([:"value#{index}"])]),
+          open_tuple([atom([String.to_unsafe_atom("value#{index}")])]),
           integer()
         ])
       )
@@ -3954,7 +3954,10 @@ defmodule Module.Types.DescrTest do
             tuple([atom([:font_style]), atom([:italic])]),
             Enum.reduce(
               for elem1 <- 1..5, elem2 <- 1..5 do
-                tuple([atom([:"f#{elem1}"]), atom([:"s#{elem2}"])])
+                tuple([
+                  atom([String.to_unsafe_atom("f#{elem1}")]),
+                  atom([String.to_unsafe_atom("s#{elem2}")])
+                ])
               end,
               &opt_union/2
             )
@@ -4008,7 +4011,7 @@ defmodule Module.Types.DescrTest do
             {:notifications, boolean()}
           ] ++
             Enum.map(1..50, fn i ->
-              {:"field_#{i}", atom([:"value_#{i}"])}
+              {String.to_unsafe_atom("field_#{i}"), atom([String.to_unsafe_atom("value_#{i}")])}
             end)
         )
 
@@ -4021,7 +4024,7 @@ defmodule Module.Types.DescrTest do
 
       expected =
         for i <- 1..50 do
-          name = :"name_#{i}"
+          name = String.to_unsafe_atom("name_#{i}")
           closed_map([__struct__: atom([name])] ++ [{name, binary()}])
         end
         |> Enum.reduce(&opt_union/2)
diff --git a/lib/elixir/test/elixir/registry/duplicate_test.exs b/lib/elixir/test/elixir/registry/duplicate_test.exs
index 87325fc4a5b..f6ee1e9f090 100644
--- a/lib/elixir/test/elixir/registry/duplicate_test.exs
+++ b/lib/elixir/test/elixir/registry/duplicate_test.exs
@@ -19,9 +19,10 @@ defmodule Registry.DuplicateTest do
     partitions = config.partitions
 
     listeners =
-      List.wrap(config[:base_listener]) |> Enum.map(&:"#{&1}_#{partitions}_#{inspect(keys)}")
+      List.wrap(config[:base_listener])
+      |> Enum.map(&String.to_unsafe_atom("#{&1}_#{partitions}_#{inspect(keys)}"))
 
-    name = :"#{config.test}_#{partitions}_#{inspect(keys)}"
+    name = String.to_unsafe_atom("#{config.test}_#{partitions}_#{inspect(keys)}")
     opts = [keys: config.keys, name: name, partitions: partitions, listeners: listeners]
     {:ok, _} = start_supervised({Registry, opts})
     %{registry: name, listeners: listeners}
@@ -476,7 +477,7 @@ defmodule Registry.DuplicateTest do
   end
 
   test "rejects invalid tuple syntax", %{partitions: partitions} do
-    name = :"test_invalid_tuple_#{partitions}"
+    name = String.to_unsafe_atom("test_invalid_tuple_#{partitions}")
 
     assert_raise ArgumentError, ~r/expected :keys to be given and be one of/, fn ->
       Registry.start_link(keys: {:duplicate, :invalid}, name: name, partitions: partitions)
diff --git a/lib/elixir/test/elixir/registry/unique_test.exs b/lib/elixir/test/elixir/registry/unique_test.exs
index 1ef16e57dce..ec3d3bb7e05 100644
--- a/lib/elixir/test/elixir/registry/unique_test.exs
+++ b/lib/elixir/test/elixir/registry/unique_test.exs
@@ -16,8 +16,11 @@ defmodule Registry.UniqueTest do
 
   setup config do
     partitions = config.partitions
-    listeners = List.wrap(config[:base_listener]) |> Enum.map(&:"#{&1}_#{partitions}")
-    name = :"#{config.test}_#{partitions}"
+
+    listeners =
+      List.wrap(config[:base_listener]) |> Enum.map(&String.to_unsafe_atom("#{&1}_#{partitions}"))
+
+    name = String.to_unsafe_atom("#{config.test}_#{partitions}")
     opts = [keys: @keys, name: name, partitions: partitions, listeners: listeners]
     {:ok, _} = start_supervised({Registry, opts})
     %{registry: name, listeners: listeners}
diff --git a/lib/elixir/test/elixir/registry_test.exs b/lib/elixir/test/elixir/registry_test.exs
index 71129cd4c7f..879980c2c72 100644
--- a/lib/elixir/test/elixir/registry_test.exs
+++ b/lib/elixir/test/elixir/registry_test.exs
@@ -24,9 +24,10 @@ defmodule Registry.Test do
     partitions = config.partitions
 
     listeners =
-      List.wrap(config[:base_listener]) |> Enum.map(&:"#{&1}_#{partitions}_#{inspect(keys)}")
+      List.wrap(config[:base_listener])
+      |> Enum.map(&String.to_unsafe_atom("#{&1}_#{partitions}_#{inspect(keys)}"))
 
-    name = :"#{config.test}_#{partitions}_#{inspect(keys)}"
+    name = String.to_unsafe_atom("#{config.test}_#{partitions}_#{inspect(keys)}")
     opts = [keys: keys, name: name, partitions: partitions, listeners: listeners]
     {:ok, _} = start_supervised({Registry, opts})
     %{registry: name, listeners: listeners}
@@ -95,7 +96,7 @@ defmodule Registry.LockTest do
   setup config do
     keys = config.keys
     partitions = config.partitions
-    name = :"#{config.test}_#{keys}_#{partitions}"
+    name = String.to_unsafe_atom("#{config.test}_#{keys}_#{partitions}")
     opts = [keys: keys, name: name, partitions: partitions]
     {:ok, _} = start_supervised({Registry, opts})
     %{registry: name}
diff --git a/lib/elixir/test/elixir/typespec_test.exs b/lib/elixir/test/elixir/typespec_test.exs
index 498099167c1..dd8705bb57b 100644
--- a/lib/elixir/test/elixir/typespec_test.exs
+++ b/lib/elixir/test/elixir/typespec_test.exs
@@ -532,7 +532,7 @@ defmodule TypespecTest do
       assert {:type, _, :map_field_exact, [{:atom, _, :message}, {:type, _, :term, []}]} = arg2
     end
 
-    @fields Enum.map(10..42, &{:"f#{&1}", :ok})
+    @fields Enum.map(10..42, &{String.to_unsafe_atom("f#{&1}"), :ok})
 
     test "@type with a large struct" do
       bytecode =
diff --git a/lib/elixir/test/elixir/uri_test.exs b/lib/elixir/test/elixir/uri_test.exs
index 0c58db61efd..678baddbe13 100644
--- a/lib/elixir/test/elixir/uri_test.exs
+++ b/lib/elixir/test/elixir/uri_test.exs
@@ -464,8 +464,8 @@ defmodule URITest do
     end
 
     test "base without host" do
-      assert URI.merge("tag:example", "foo") |> to_string == "tag:foo"
-      assert URI.merge("tag:example", "#fragment") |> to_string == "tag:example#fragment"
+      assert URI.merge("tag:example", "foo") |> to_string() == "tag:foo"
+      assert URI.merge("tag:example", "#fragment") |> to_string() == "tag:example#fragment"
     end
 
     test "base without host and path" do
diff --git a/lib/ex_unit/lib/ex_unit/assertions.ex b/lib/ex_unit/lib/ex_unit/assertions.ex
index d6dc5ee7fda..c996852960a 100644
--- a/lib/ex_unit/lib/ex_unit/assertions.ex
+++ b/lib/ex_unit/lib/ex_unit/assertions.ex
@@ -361,7 +361,7 @@ defmodule ExUnit.Assertions do
 
     case Macro.expand_once(expr, env) do
       ^expr when not reserved? and not all_quoted_literals? ->
-        vars = for i <- 1..arity, do: Macro.var(:"arg#{i}", __MODULE__)
+        vars = for i <- 1..arity, do: Macro.var(String.to_unsafe_atom("arg#{i}"), __MODULE__)
 
         quoted =
           quote do
diff --git a/lib/ex_unit/lib/ex_unit/callbacks.ex b/lib/ex_unit/lib/ex_unit/callbacks.ex
index 02a5e51a5f6..5c116c7a8fc 100644
--- a/lib/ex_unit/lib/ex_unit/callbacks.ex
+++ b/lib/ex_unit/lib/ex_unit/callbacks.ex
@@ -291,8 +291,11 @@ defmodule ExUnit.Callbacks do
 
     name =
       case Module.get_attribute(module, :ex_unit_describe) do
-        {_line, _message, counter} -> :"__ex_unit_setup_#{counter}_#{length(setup)}"
-        nil -> :"__ex_unit_setup_#{length(setup)}"
+        {_line, _message, counter} ->
+          String.to_unsafe_atom("__ex_unit_setup_#{counter}_#{length(setup)}")
+
+        nil ->
+          String.to_unsafe_atom("__ex_unit_setup_#{length(setup)}")
       end
 
     Module.put_attribute(module, :ex_unit_setup, [name | setup])
@@ -425,7 +428,7 @@ defmodule ExUnit.Callbacks do
   def __setup_all__(module) do
     no_describe!(module)
     setup_all = Module.get_attribute(module, :ex_unit_setup_all)
-    name = :"__ex_unit_setup_all_#{length(setup_all)}"
+    name = String.to_unsafe_atom("__ex_unit_setup_all_#{length(setup_all)}")
     Module.put_attribute(module, :ex_unit_setup_all, [name | setup_all])
     name
   end
@@ -828,7 +831,8 @@ defmodule ExUnit.Callbacks do
           {nil, nil}
 
         callbacks ->
-          {:"__ex_unit_describe_#{map_size(used_describes)}", compile_setup(callbacks, :setup)}
+          {String.to_unsafe_atom("__ex_unit_describe_#{map_size(used_describes)}"),
+           compile_setup(callbacks, :setup)}
       end
 
     used_describes = Map.put(used_describes, message, name)
diff --git a/lib/ex_unit/test/ex_unit/failures_manifest_test.exs b/lib/ex_unit/test/ex_unit/failures_manifest_test.exs
index 06808d2f77c..219f723d36a 100644
--- a/lib/ex_unit/test/ex_unit/failures_manifest_test.exs
+++ b/lib/ex_unit/test/ex_unit/failures_manifest_test.exs
@@ -205,7 +205,7 @@ defmodule ExUnit.FailuresManifestTest do
     %ExUnit.Test{
       state: state,
       module: SomeMod,
-      name: :"test #{System.unique_integer()}",
+      name: String.to_unsafe_atom("test #{System.unique_integer()}"),
       tags: %{file: file}
     }
   end
diff --git a/lib/mix/lib/mix/dep/converger.ex b/lib/mix/lib/mix/dep/converger.ex
index 1d7b0deade3..98accde6fab 100644
--- a/lib/mix/lib/mix/dep/converger.ex
+++ b/lib/mix/lib/mix/dep/converger.ex
@@ -346,11 +346,11 @@ defmodule Mix.Dep.Converger do
           {:ok, value} ->
             case List.wrap(value) -- List.wrap(other_value) do
               [] -> other
-              _ -> %{other | status: {:"diverged#{key}", dep}}
+              _ -> %{other | status: {String.to_unsafe_atom("diverged#{key}"), dep}}
             end
 
           :error ->
-            %{other | status: {:"diverged#{key}", dep}}
+            %{other | status: {String.to_unsafe_atom("diverged#{key}"), dep}}
         end
 
       :error ->
diff --git a/lib/mix/lib/mix/generator.ex b/lib/mix/lib/mix/generator.ex
index e04e4ca30dd..bbe2d0f18b8 100644
--- a/lib/mix/lib/mix/generator.ex
+++ b/lib/mix/lib/mix/generator.ex
@@ -216,7 +216,10 @@ defmodule Mix.Generator do
       require EEx
 
       source = "<% _ = assigns %>" <> contents
-      EEx.function_from_string(:defp, :"#{name}_template", source, [:assigns])
+
+      EEx.function_from_string(:defp, String.to_unsafe_atom("#{name}_template"), source, [
+        :assigns
+      ])
     end
   end
 
@@ -243,7 +246,7 @@ defmodule Mix.Generator do
           _ -> raise ArgumentError, "expected string or from_file: file"
         end
 
-      defp unquote(:"#{name}_text")(), do: unquote(contents)
+      defp unquote(String.to_unsafe_atom("#{name}_text"))(), do: unquote(contents)
     end
   end
 end
diff --git a/lib/mix/lib/mix/task.ex b/lib/mix/lib/mix/task.ex
index d336ba639cd..72d7d112e26 100644
--- a/lib/mix/lib/mix/task.ex
+++ b/lib/mix/lib/mix/task.ex
@@ -188,7 +188,7 @@ defmodule Mix.Task do
 
     case base do
       <<"Elixir.Mix.Tasks.", rest::binary-size(^part), ".beam">> ->
-        mod = :"Elixir.Mix.Tasks.#{rest}"
+        mod = String.to_unsafe_atom("Elixir.Mix.Tasks.#{rest}")
         ensure_task?(mod) && mod
 
       _ ->
diff --git a/lib/mix/lib/mix/tasks/archive.install.ex b/lib/mix/lib/mix/tasks/archive.install.ex
index de27e5d9d83..13814c64f95 100644
--- a/lib/mix/lib/mix/tasks/archive.install.ex
+++ b/lib/mix/lib/mix/tasks/archive.install.ex
@@ -176,7 +176,7 @@ defmodule Mix.Tasks.Archive.Install do
     type = elem(file_info, 2)
     path = zip_path_to_string(path)
 
-    unless type in [:regular, :directory] do
+    if type not in [:regular, :directory] do
       Mix.raise(
         "Installation failed: invalid archive file, #{inspect(path)} is not a regular file or directory"
       )
diff --git a/lib/mix/lib/mix/tasks/deps.clean.ex b/lib/mix/lib/mix/tasks/deps.clean.ex
index 5e59334c80a..9ee1470fff9 100644
--- a/lib/mix/lib/mix/tasks/deps.clean.ex
+++ b/lib/mix/lib/mix/tasks/deps.clean.ex
@@ -43,7 +43,7 @@ defmodule Mix.Tasks.Deps.Clean do
     loaded_opts =
       for {switch, key} <- [only: :env, target: :target],
           value = opts[switch],
-          do: {key, :"#{value}"}
+          do: {key, String.to_unsafe_atom("#{value}")}
 
     loaded_deps = Mix.Dep.Converger.converge(loaded_opts)
 
diff --git a/lib/mix/lib/mix/tasks/deps.get.ex b/lib/mix/lib/mix/tasks/deps.get.ex
index c57b53dad16..5d96ea6f493 100644
--- a/lib/mix/lib/mix/tasks/deps.get.ex
+++ b/lib/mix/lib/mix/tasks/deps.get.ex
@@ -38,7 +38,7 @@ defmodule Mix.Tasks.Deps.Get do
     fetch_opts =
       for {switch, key} <- [only: :env, target: :target, check_locked: :check_locked],
           value = opts[switch],
-          do: {key, :"#{value}"}
+          do: {key, String.to_unsafe_atom("#{value}")}
 
     apps = Mix.Dep.Fetcher.all(%{}, Mix.Dep.Lock.read(), fetch_opts)
 
diff --git a/lib/mix/lib/mix/tasks/deps.tree.ex b/lib/mix/lib/mix/tasks/deps.tree.ex
index 6a59be32e65..3623b13ca5c 100644
--- a/lib/mix/lib/mix/tasks/deps.tree.ex
+++ b/lib/mix/lib/mix/tasks/deps.tree.ex
@@ -85,7 +85,7 @@ defmodule Mix.Tasks.Deps.Tree do
     deps_opts =
       for {switch, key} <- [only: :env, target: :target],
           value = opts[switch],
-          do: {key, :"#{value}"}
+          do: {key, String.to_unsafe_atom("#{value}")}
 
     deps = Mix.Dep.Converger.converge(deps_opts)
 
diff --git a/lib/mix/lib/mix/tasks/deps.update.ex b/lib/mix/lib/mix/tasks/deps.update.ex
index f9bed188fa9..6edabc3e2f6 100644
--- a/lib/mix/lib/mix/tasks/deps.update.ex
+++ b/lib/mix/lib/mix/tasks/deps.update.ex
@@ -58,7 +58,7 @@ defmodule Mix.Tasks.Deps.Update do
     fetch_opts =
       for {switch, key} <- [only: :env, target: :target],
           value = opts[switch],
-          do: {key, :"#{value}"}
+          do: {key, String.to_unsafe_atom("#{value}")}
 
     cond do
       opts[:all] ->
diff --git a/lib/mix/test/mix/tasks/release_test.exs b/lib/mix/test/mix/tasks/release_test.exs
index 4a79df298c7..aebcb44a548 100644
--- a/lib/mix/test/mix/tasks/release_test.exs
+++ b/lib/mix/test/mix/tasks/release_test.exs
@@ -10,7 +10,7 @@ defmodule Mix.Tasks.ReleaseTest do
   @erts_version :erlang.system_info(:version)
   @hostname :inet_db.gethostname()
 
-  defmacrop release_node(name), do: :"#{name}@#{@hostname}"
+  defmacrop release_node(name), do: String.to_unsafe_atom("#{name}@#{@hostname}")
 
   describe "customize" do
     test "env, vm.args and overlays templates" do