diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index aa9ea90..64e63e9 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -16,7 +16,7 @@ jobs:
       matrix:
         os: [ ubuntu-16.04, ubuntu-18.04, macos-latest, windows-latest ]
         # Use various version syntaxes here for testing
-        ruby: [ 2.2, 2.3, .ruby-version, .tool-versions, ruby-head, jruby, jruby-head, truffleruby, truffleruby-head ]
+        ruby: [ 2.2, 2.3, .ruby-version, .tool-versions, ruby-head, jruby-9.1, jruby, jruby-head, truffleruby, truffleruby-head ]
         exclude:
         - os: windows-latest
           ruby: truffleruby
diff --git a/README.md b/README.md
index 096a50f..602ec84 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ This action currently supports these versions of MRI, JRuby and TruffleRuby:
 | Interpreter | Versions |
 | ----------- | -------- |
 | Ruby | 2.2, 2.3.0 - 2.3.8, 2.4.0 - 2.4.9, 2.5.0 - 2.5.7, 2.6.0 - 2.6.5, 2.7.0, head, mingw, mswin |
-| JRuby | 9.2.9.0 - 9.2.11.0, head |
+| JRuby | 9.1.17.0, 9.2.9.0 - 9.2.11.0, head |
 | TruffleRuby | 19.3.0 - 20.0.0, head |
 | Rubinius | 4.14 |
 
diff --git a/dist/index.js b/dist/index.js
index 3c8d7ed..df6eb9e 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -1393,6 +1393,7 @@ function getVersions(platform) {
       "head"
     ],
     "jruby": [
+      "9.1.17.0",
       "9.2.9.0", "9.2.10.0", "9.2.11.0",
       "head"
     ],
diff --git a/ruby-builder-versions.js b/ruby-builder-versions.js
index d1a3d75..d8b674f 100644
--- a/ruby-builder-versions.js
+++ b/ruby-builder-versions.js
@@ -10,7 +10,8 @@ export function getVersions(platform) {
       "head"
     ],
     "jruby": [
-      "9.1.17.0", "9.2.9.0", "9.2.10.0", "9.2.11.0",
+      "9.1.17.0",
+      "9.2.9.0", "9.2.10.0", "9.2.11.0",
       "head"
     ],
     "truffleruby": [