diff --git a/.github/workflows/zjit-macos.yml b/.github/workflows/zjit-macos.yml
index 8e5ca954cb..30024a6d0c 100644
--- a/.github/workflows/zjit-macos.yml
+++ b/.github/workflows/zjit-macos.yml
@@ -40,6 +40,7 @@ jobs:
 
           - test_task: 'zjit-test-all'
             configure: '--enable-zjit=dev'
+            testopts: '--seed=11831'
 
           - test_task: 'btest'
             configure: '--enable-zjit=dev'
@@ -48,6 +49,7 @@ jobs:
       GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
       RUN_OPTS: ${{ matrix.zjit_opts }}
       SPECOPTS: ${{ matrix.specopts }}
+      TESTOPTS: ${{ matrix.testopts }}
 
     runs-on: macos-14
 
@@ -146,6 +148,7 @@ jobs:
           make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"}
           RUN_OPTS="$RUN_OPTS"
           SPECOPTS="$SPECOPTS"
+          TESTOPTS="$TESTOPTS"
         timeout-minutes: 60
         env:
           RUBY_TESTOPTS: '-q --tty=no'
diff --git a/.github/workflows/zjit-ubuntu.yml b/.github/workflows/zjit-ubuntu.yml
index ecfd0ddede..3e2db58f72 100644
--- a/.github/workflows/zjit-ubuntu.yml
+++ b/.github/workflows/zjit-ubuntu.yml
@@ -42,6 +42,7 @@ jobs:
 
           - test_task: 'zjit-test-all'
             configure: '--enable-zjit=dev'
+            testopts: '--seed=11831'
 
           - test_task: 'btest'
             configure: '--enable-zjit=dev'
@@ -51,6 +52,7 @@ jobs:
       RUN_OPTS: ${{ matrix.zjit_opts }}
       YJIT_BENCH_OPTS: ${{ matrix.yjit_bench_opts }}
       SPECOPTS: ${{ matrix.specopts }}
+      TESTOPTS: ${{ matrix.testopts }}
       RUBY_DEBUG: ci
       BUNDLE_JOBS: 8 # for yjit-bench
       RUST_BACKTRACE: 1
@@ -167,6 +169,7 @@ jobs:
         run: >-
           make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"}
           RUN_OPTS="$RUN_OPTS" MSPECOPT=--debug SPECOPTS="$SPECOPTS"
+          TESTOPTS="$TESTOPTS"
           ZJIT_BINDGEN_DIFF_OPTS="$ZJIT_BINDGEN_DIFF_OPTS"
         timeout-minutes: 90
         env: