diff --git a/.env b/.env
index 9d17a1c..839106d 100644
--- a/.env
+++ b/.env
@@ -1,2 +1,2 @@
-OTP_VERSION=27.1.2
-REBAR_VERSION=3.24
\ No newline at end of file
+OTP_VERSION=28.5.0
+REBAR_VERSION=3.26
\ No newline at end of file
diff --git a/.github/workflows/erlang-checks.yml b/.github/workflows/erlang-checks.yml
index da30f02..21412ba 100644
--- a/.github/workflows/erlang-checks.yml
+++ b/.github/workflows/erlang-checks.yml
@@ -26,7 +26,7 @@ jobs:
   run:
     name: Run checks
     needs: setup
-    uses: valitydev/erlang-workflows/.github/workflows/erlang-parallel-build.yml@v1.0.16
+    uses: valitydev/erlang-workflows/.github/workflows/erlang-parallel-build.yml@v1
     with:
       otp-version: ${{ needs.setup.outputs.otp-version }}
       rebar-version: ${{ needs.setup.outputs.rebar-version }}
diff --git a/src/genlib_rational.erl b/src/genlib_rational.erl
index db728c1..b99a100 100644
--- a/src/genlib_rational.erl
+++ b/src/genlib_rational.erl
@@ -33,7 +33,7 @@
 
 %%
 
--opaque t() :: {integer(), pos_integer()}.
+-type t() :: {integer(), pos_integer()}.
 
 -type rounding_method() :: round_half_towards_zero | round_half_away_from_zero.
 
diff --git a/test/prop_genlib_map.erl b/test/prop_genlib_map.erl
index b4613f2..b5ee0e8 100644
--- a/test/prop_genlib_map.erl
+++ b/test/prop_genlib_map.erl
@@ -114,9 +114,6 @@ maps_common_keys(LeftMap, RightMap) ->
         )
     ).
 
-map() ->
-    ?LET(KVList, list({term(), term()}), maps:from_list(KVList)).
-
 non_empty_map() ->
     ?LET(KVList, non_empty(list({term(), term()})), maps:from_list(KVList)).