diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 8eda42633..ef4d17d72 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.6', '2.7']
+        ruby-version: ['2.7']
 
     steps:
     - uses: actions/checkout@v2
diff --git a/.gitignore b/.gitignore
index cafbb7956..74a895970 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,7 +2,6 @@
 **/coverage/**
 fhir_models*log*
 invariants.txt
-.ruby-version
 .ruby-gemset
 tmp/
 
diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 000000000..a4dd9dba4
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+2.7.4
diff --git a/.tool-versions b/.tool-versions
new file mode 100644
index 000000000..1ade73219
--- /dev/null
+++ b/.tool-versions
@@ -0,0 +1 @@
+ruby 2.7.4
diff --git a/Gemfile.lock b/Gemfile.lock
index e4f86e1d3..0c98954fd 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -51,10 +51,10 @@ GEM
     mime-types (3.4.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2022.0105)
-    mini_portile2 (2.5.3)
+    mini_portile2 (2.8.5)
     nenv (0.3.0)
-    nokogiri (1.11.7)
-      mini_portile2 (~> 2.5.0)
+    nokogiri (1.15.5)
+      mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     nokogiri-diff (0.2.0)
       nokogiri (~> 1.5)
@@ -71,7 +71,7 @@ GEM
       method_source (~> 1.0)
     pry-coolline (0.2.5)
       coolline (~> 0.5)
-    racc (1.5.2)
+    racc (1.7.3)
     rainbow (3.0.0)
     rake (13.0.1)
     rb-fsevent (0.10.4)