diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 539cae6b3..45004a91d 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -11,7 +11,7 @@ env:
   LLVM_RELEASE_VERSION_MAC: 17
   LLVM_RELEASE_VERSION_LINUX: 17
   LLVM_RELEASE_VERSION_UBUNTU20: 17
-  LLVM_DEV_VERSION: 20
+  LLVM_DEV_VERSION: 21
 jobs:
 
   build-msvc:
@@ -228,7 +228,7 @@ jobs:
       fail-fast: false
       matrix:
         build_type: [Release, Debug]
-        llvm_version: [17, 18, 19, 20]
+        llvm_version: [17, 18, 19, 20, 21]
 
     steps:
       - uses: actions/checkout@v4
@@ -405,7 +405,7 @@ jobs:
       fail-fast: false
       matrix:
         build_type: [Release, Debug]
-        llvm_version: [17, 18, 19, 20]
+        llvm_version: [17, 18, 19, 20, 21]
     steps:
       - uses: actions/checkout@v4
       - name: Install common deps
@@ -526,7 +526,7 @@ jobs:
       matrix:
         ubuntu_version: [20.04, 22.04]
         build_type: [Release, Debug]
-        llvm_version: [17, 18, 19, 20]
+        llvm_version: [17, 18, 19, 20, 21]
 
     steps:
       - uses: actions/checkout@v4