diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 0266f9e..9b9da51 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -57,7 +57,7 @@ jobs:
 
       - name: Stan build caching
         # note: not quite working since we use a development branch of Stan
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         id: stan-cache
         with:
           path: ./stan/
@@ -65,7 +65,7 @@ jobs:
 
       # we use the cache here to build the Stan models once for multiple interfaces
       - name: Set up test model cache
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         id: test-models
         with:
           path: ./test_models/
@@ -90,7 +90,7 @@ jobs:
           submodules: recursive
 
       - name: Restore Stan
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         id: stan-cache
         with:
           fail-on-cache-miss: true
@@ -98,7 +98,7 @@ jobs:
           key: ${{ matrix.os }}-stan-${{ hashFiles('stan/src/stan/version.hpp') }}-v${{ env.CACHE_VERSION }}
 
       - name: Restore built models
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         id: test-models
         with:
           fail-on-cache-miss: true
@@ -146,7 +146,7 @@ jobs:
           submodules: recursive
 
       - name: Restore Stan
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         id: stan-cache
         with:
           fail-on-cache-miss: true
@@ -154,7 +154,7 @@ jobs:
           key: ${{ matrix.os }}-stan-${{ hashFiles('stan/src/stan/version.hpp') }}-v${{ env.CACHE_VERSION }}
 
       - name: Restore built models
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         id: test-models
         with:
           fail-on-cache-miss: true
@@ -205,7 +205,7 @@ jobs:
           submodules: recursive
 
       - name: Restore Stan
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         id: stan-cache
         with:
           fail-on-cache-miss: true
@@ -213,7 +213,7 @@ jobs:
           key: ${{ matrix.os }}-stan-${{ hashFiles('stan/src/stan/version.hpp') }}-v${{ env.CACHE_VERSION }}
 
       - name: Restore built models
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         id: test-models
         with:
           fail-on-cache-miss: true