diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cdac8a679..850de6d28 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -68,7 +68,7 @@ jobs:
             shell: bash
           - target:
               os: macos
-            builder: macos-10.15
+            builder: macos-11
             shell: bash
           - target:
               os: windows
@@ -257,12 +257,12 @@ jobs:
         id: nim-cache
         uses: actions/cache@v2
         with:
-          path: NimBinaries
+          path: NimBinCache
           key: 'nim-${{ matrix.target.os }}-${{ matrix.target.cpu }}-${{ steps.versions.outputs.nimbus_build_system }}'
 
       - name: Build Nim and Nimbus-eth1 dependencies
         run: |
-          make -j${ncpu} ARCH_OVERRIDE=${PLATFORM} CI_CACHE=NimBinaries update
+          make -j${ncpu} ARCH_OVERRIDE=${PLATFORM} CI_CACHE=NimBinCache update
 
       - name: Run nimbus-eth1 tests (Windows)
         if: runner.os == 'Windows'
diff --git a/.github/workflows/fluffy.yml b/.github/workflows/fluffy.yml
index 26c845c31..a96ab04c4 100644
--- a/.github/workflows/fluffy.yml
+++ b/.github/workflows/fluffy.yml
@@ -114,7 +114,7 @@ jobs:
             shell: bash
           - target:
               os: macos
-            builder: macos-10.15
+            builder: macos-11
             shell: bash
           - target:
               os: windows
diff --git a/.github/workflows/simulators.yml b/.github/workflows/simulators.yml
index 6d0cca797..15263321c 100644
--- a/.github/workflows/simulators.yml
+++ b/.github/workflows/simulators.yml
@@ -51,7 +51,7 @@ jobs:
 
   build-macos-amd64:
     name: Macos-amd64
-    runs-on: macos-10.15
+    runs-on: macos-11
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
diff --git a/hive_integration/nodocker/build_sims.sh b/hive_integration/nodocker/build_sims.sh
index ea1a88b89..0827c91a8 100644
--- a/hive_integration/nodocker/build_sims.sh
+++ b/hive_integration/nodocker/build_sims.sh
@@ -7,12 +7,17 @@ USE_SYSTEM_NIM=1
 ENV_SCRIPT="vendor/nimbus-build-system/scripts/env.sh"
 
 # nimbus_db_backend:none -> we only use memory db in simulators
-NIM_FLAGS="c -r -d:release -d:disable_libbacktrace -d:nimbus_db_backend:none"
+NIM_FLAGS="c -d:release -d:disable_libbacktrace -d:nimbus_db_backend:none"
 
 ${ENV_SCRIPT} nim ${NIM_FLAGS} ${SIM_DIR}/engine/engine_sim
 ${ENV_SCRIPT} nim ${NIM_FLAGS} ${SIM_DIR}/consensus/consensus_sim
 ${ENV_SCRIPT} nim ${NIM_FLAGS} ${SIM_DIR}/graphql/graphql_sim
 ${ENV_SCRIPT} nim ${NIM_FLAGS} ${SIM_DIR}/rpc/rpc_sim
 
+${SIM_DIR}/engine/engine_sim
+${SIM_DIR}/consensus/consensus_sim
+${SIM_DIR}/graphql/graphql_sim
+${SIM_DIR}/rpc/rpc_sim
+
 echo "## ${1}" > simulators.md
 cat engine.md consensus.md graphql.md rpc.md >> simulators.md