diff --git a/__test__/find.unit.test.ts b/__test__/find.unit.test.ts
index 381370a..c2375c2 100644
--- a/__test__/find.unit.test.ts
+++ b/__test__/find.unit.test.ts
@@ -210,6 +210,26 @@ describe('find comment tests', () => {
       )
     ).toEqual(true)
 
+    expect(
+      findCommentPredicate(
+        {
+          token: 'token',
+          repository: 'repository',
+          issueNumber: 1,
+          commentAuthor: 'dorothy',
+          bodyIncludes: '',
+          bodyRegex: '/^.*KaNsAs.*$/i',
+          direction: 'direction'
+        },
+        {
+          id: 1,
+          body: `Toto, I've a feeling we're not in Kansas anymore.`,
+          user: {login: 'dorothy'},
+          created_at: '2020-01-01T00:00:00Z'
+        }
+      )
+    ).toEqual(true)
+
     expect(
       findCommentPredicate(
         {
diff --git a/dist/index.js b/dist/index.js
index 9c71fc4..90d910b 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -48,6 +48,13 @@ var __asyncValues = (this && this.__asyncValues) || function (o) {
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.findComment = exports.findCommentPredicate = void 0;
 const github = __importStar(__nccwpck_require__(5438));
+function stringToRegex(s) {
+    const m = s.match(/^(.)(.*?)\1([gimsuy]*)$/);
+    if (m)
+        return new RegExp(m[2], m[3]);
+    else
+        return new RegExp(s);
+}
 function findCommentPredicate(inputs, comment) {
     return ((inputs.commentAuthor && comment.user
         ? comment.user.login === inputs.commentAuthor
@@ -56,7 +63,7 @@ function findCommentPredicate(inputs, comment) {
             ? comment.body.includes(inputs.bodyIncludes)
             : true) &&
         (inputs.bodyRegex && comment.body
-            ? comment.body.match(inputs.bodyRegex) !== null
+            ? comment.body.match(stringToRegex(inputs.bodyRegex)) !== null
             : true));
 }
 exports.findCommentPredicate = findCommentPredicate;
diff --git a/src/find.ts b/src/find.ts
index 5c28771..5aa54a9 100644
--- a/src/find.ts
+++ b/src/find.ts
@@ -19,6 +19,12 @@ export interface Comment {
   created_at: string
 }
 
+function stringToRegex(s: string): RegExp {
+  const m = s.match(/^(.)(.*?)\1([gimsuy]*)$/)
+  if (m) return new RegExp(m[2], m[3])
+  else return new RegExp(s)
+}
+
 export function findCommentPredicate(
   inputs: Inputs,
   comment: Comment
@@ -31,7 +37,7 @@ export function findCommentPredicate(
       ? comment.body.includes(inputs.bodyIncludes)
       : true) &&
     (inputs.bodyRegex && comment.body
-      ? comment.body.match(inputs.bodyRegex) !== null
+      ? comment.body.match(stringToRegex(inputs.bodyRegex)) !== null
       : true)
   )
 }