diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 04c501c47..91da9ad69 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -61,7 +61,7 @@ jobs:
       matrix:
         include:
           - image: swiftlang/swift:nightly-jammy
-            swift-version: main
+            swift-version: 'main'
             env:
               MAX_ALLOCS_ALLOWED_bidi_1k_rpcs_10_requests: 323000
               MAX_ALLOCS_ALLOWED_bidi_1k_rpcs_1_request: 161000
@@ -72,7 +72,7 @@ jobs:
               MAX_ALLOCS_ALLOWED_unary_1k_ping_pong_interceptors_client: 170000
               MAX_ALLOCS_ALLOWED_unary_1k_ping_pong_interceptors_server: 170000
           - image: swiftlang/swift:nightly-6.0-jammy
-            swift-version: main
+            swift-version: '6.0'
             env:
               MAX_ALLOCS_ALLOWED_bidi_1k_rpcs_10_requests: 323000
               MAX_ALLOCS_ALLOWED_bidi_1k_rpcs_1_request: 161000
@@ -126,9 +126,11 @@ jobs:
       env: ${{ matrix.env }}
       timeout-minutes: 20
     - name: Install jemalloc for benchmarking
+      if: ${{ swift-version == '6.0' || swift-version == 'main' }}
       run: apt update && apt-get install -y libjemalloc-dev
       timeout-minutes: 20
     - name: Run Benchmarks
+      if: ${{ swift-version == '6.0' || swift-version == 'main' }}
       working-directory: ./Performance/Benchmarks
       run: swift package benchmark baseline check --no-progress --check-absolute-path Thresholds/${{ matrix.swift-version }}/
       timeout-minutes: 20