diff --git a/.github/workflows/integration-arm64.yaml b/.github/workflows/integration-arm64.yaml
index 873daaa74..d34d28c3c 100644
--- a/.github/workflows/integration-arm64.yaml
+++ b/.github/workflows/integration-arm64.yaml
@@ -7,6 +7,11 @@ concurrency:
 jobs:
   build:
     timeout-minutes: 120
+    env:
+      # Our runner has 80 cores (nproc).
+      # We limit parallelism only to avoid exhausting disk space and memory
+      # resources, not to save CPU resources.
+      PARALLEL_INTEGRATION_TESTS_NUM: 25
     name: Tests (ARM64)
     runs-on: ${{ github.event_name == 'pull_request' && 'ubuntu-latest' || 'bookworm-arm64' }}
     steps:
diff --git a/.github/workflows/integration-x86-64.yaml b/.github/workflows/integration-x86-64.yaml
index 98e2a8dcd..213442d98 100644
--- a/.github/workflows/integration-x86-64.yaml
+++ b/.github/workflows/integration-x86-64.yaml
@@ -7,6 +7,11 @@ concurrency:
 jobs:
   build:
     timeout-minutes: 80
+    env:
+      # Our runner has 16 cores (nproc).
+      # We limit parallelism only to avoid exhausting disk space and memory
+      # resources, not to save CPU resources.
+      PARALLEL_INTEGRATION_TESTS_NUM: 12
     strategy:
       fail-fast: false
       matrix:
diff --git a/scripts/dev_cli.sh b/scripts/dev_cli.sh
index 3b9451321..a5d3947ce 100755
--- a/scripts/dev_cli.sh
+++ b/scripts/dev_cli.sh
@@ -512,6 +512,7 @@ cmd_tests() {
             --env BUILD_TARGET="$target" \
             --env RUSTFLAGS="$rustflags" \
             --env TARGET_CC="$target_cc" \
+            --env PARALLEL_INTEGRATION_TESTS_NUM="${PARALLEL_INTEGRATION_TESTS_NUM:-}" \
             --env AUTH_DOWNLOAD_TOKEN="$AUTH_DOWNLOAD_TOKEN" \
             --env LLVM_PROFILE_FILE="$LLVM_PROFILE_FILE" \
             "$CTR_IMAGE" \
@@ -613,6 +614,7 @@ cmd_tests() {
             --env BUILD_TARGET="$target" \
             --env RUSTFLAGS="$rustflags" \
             --env TARGET_CC="$target_cc" \
+            --env PARALLEL_INTEGRATION_TESTS_NUM="${PARALLEL_INTEGRATION_TESTS_NUM:-}" \
             --env AUTH_DOWNLOAD_TOKEN="$AUTH_DOWNLOAD_TOKEN" \
             --env LLVM_PROFILE_FILE="$LLVM_PROFILE_FILE" \
             --env MIGRATABLE_VERSION="$MIGRATABLE_VERSION" \
diff --git a/scripts/run_integration_tests_aarch64.sh b/scripts/run_integration_tests_aarch64.sh
index 5a1dce52b..fb9d5daa5 100755
--- a/scripts/run_integration_tests_aarch64.sh
+++ b/scripts/run_integration_tests_aarch64.sh
@@ -247,8 +247,13 @@ PAGE_NUM=$((12288 * 1024 / HUGEPAGESIZE))
 echo "$PAGE_NUM" | sudo tee /proc/sys/vm/nr_hugepages
 sudo chmod a+rwX /dev/hugepages
 
+TEST_THREADS_DEFAULT="$(($(nproc) / 4))"
+if ! [[ "${PARALLEL_INTEGRATION_TESTS_NUM:-}" =~ ^[1-9][0-9]*$ ]]; then
+    PARALLEL_INTEGRATION_TESTS_NUM="${TEST_THREADS_DEFAULT}"
+fi
+echo "nproc:$(nproc), parallel_integration_tests:${PARALLEL_INTEGRATION_TESTS_NUM}"
 # Run all direct kernel boot (Device Tree) test cases in mod `parallel`
-time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "common_parallel::$test_filter" -- ${test_binary_args[*]}
+time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="${PARALLEL_INTEGRATION_TESTS_NUM}" "common_parallel::$test_filter" -- ${test_binary_args[*]}
 RES=$?
 
 # Run some tests in sequence since the result could be affected by other tests
@@ -262,7 +267,7 @@ fi
 
 # Run all ACPI test cases
 if [ $RES -eq 0 ]; then
-    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "aarch64_acpi::$test_filter" -- ${test_binary_args[*]}
+    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="$TEST_THREADS_DEFAULT" "aarch64_acpi::$test_filter" -- ${test_binary_args[*]}
     RES=$?
 else
     exit $RES
@@ -270,7 +275,7 @@ fi
 
 # Run all test cases related to live migration
 if [ $RES -eq 0 ]; then
-    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "live_migration_parallel::$test_filter" -- ${test_binary_args[*]}
+    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="$TEST_THREADS_DEFAULT" "live_migration_parallel::$test_filter" -- ${test_binary_args[*]}
     RES=$?
 else
     exit $RES
@@ -288,7 +293,7 @@ if [ $RES -eq 0 ]; then
     cargo build --features "mshv,dbus_api" --all --release --target "$BUILD_TARGET"
     export RUST_BACKTRACE=1
     # integration tests now do not reply on build feature "dbus_api"
-    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "dbus_api::$test_filter" -- ${test_binary_args[*]}
+    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="$TEST_THREADS_DEFAULT" "dbus_api::$test_filter" -- ${test_binary_args[*]}
     RES=$?
 fi
 
@@ -296,14 +301,14 @@ fi
 if [ $RES -eq 0 ]; then
     cargo build --features "mshv,fw_cfg" --all --release --target "$BUILD_TARGET"
     export RUST_BACKTRACE=1
-    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "fw_cfg::$test_filter" -- ${test_binary_args[*]}
+    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="$TEST_THREADS_DEFAULT" "fw_cfg::$test_filter" -- ${test_binary_args[*]}
     RES=$?
 fi
 
 if [ $RES -eq 0 ]; then
     cargo build --features "mshv,ivshmem" --all --release --target "$BUILD_TARGET"
     export RUST_BACKTRACE=1
-    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "ivshmem::$test_filter" -- ${test_binary_args[*]}
+    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="$TEST_THREADS_DEFAULT" "ivshmem::$test_filter" -- ${test_binary_args[*]}
 
     RES=$?
 fi
diff --git a/scripts/run_integration_tests_live_migration.sh b/scripts/run_integration_tests_live_migration.sh
index 11cf59b41..5198e2c89 100755
--- a/scripts/run_integration_tests_live_migration.sh
+++ b/scripts/run_integration_tests_live_migration.sh
@@ -87,7 +87,13 @@ sudo chmod a+rwX /dev/hugepages
 export RUST_BACKTRACE=1
 export RUSTFLAGS="$RUSTFLAGS"
 
-time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "live_migration_parallel::$test_filter" -- ${test_binary_args[*]}
+TEST_THREADS_DEFAULT="$(($(nproc) / 4))"
+if ! [[ "${PARALLEL_INTEGRATION_TESTS_NUM:-}" =~ ^[1-9][0-9]*$ ]]; then
+    PARALLEL_INTEGRATION_TESTS_NUM="${TEST_THREADS_DEFAULT}"
+fi
+echo "nproc:$(nproc), parallel_integration_tests:${PARALLEL_INTEGRATION_TESTS_NUM}"
+
+time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="${PARALLEL_INTEGRATION_TESTS_NUM}" "live_migration_parallel::$test_filter" -- ${test_binary_args[*]}
 
 RES=$?
 
diff --git a/scripts/run_integration_tests_x86_64.sh b/scripts/run_integration_tests_x86_64.sh
index f12fa9aaa..d4bf92847 100755
--- a/scripts/run_integration_tests_x86_64.sh
+++ b/scripts/run_integration_tests_x86_64.sh
@@ -189,7 +189,12 @@ ulimit -n 4096
 export RUST_BACKTRACE=1
 export RUSTFLAGS="$RUSTFLAGS"
 
-time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "common_parallel::$test_filter" -- ${test_binary_args[*]}
+TEST_THREADS_DEFAULT="$(($(nproc) / 4))"
+if ! [[ "${PARALLEL_INTEGRATION_TESTS_NUM:-}" =~ ^[1-9][0-9]*$ ]]; then
+    PARALLEL_INTEGRATION_TESTS_NUM="${TEST_THREADS_DEFAULT}"
+fi
+echo "nproc:$(nproc), parallel_integration_tests:${PARALLEL_INTEGRATION_TESTS_NUM}"
+time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="${PARALLEL_INTEGRATION_TESTS_NUM}" "common_parallel::$test_filter" -- ${test_binary_args[*]}
 RES=$?
 
 # Run some tests in sequence since the result could be affected by other tests
@@ -203,20 +208,20 @@ fi
 if [ $RES -eq 0 ]; then
     cargo build --features "mshv,dbus_api" --all --release --target "$BUILD_TARGET"
     # integration tests now do not reply on build feature "dbus_api"
-    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "dbus_api::$test_filter" -- ${test_binary_args[*]}
+    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="$TEST_THREADS_DEFAULT" "dbus_api::$test_filter" -- ${test_binary_args[*]}
     RES=$?
 fi
 
 # Run tests on fw_cfg
 if [ $RES -eq 0 ]; then
     cargo build --features "mshv,fw_cfg" --all --release --target "$BUILD_TARGET"
-    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "fw_cfg::$test_filter" -- ${test_binary_args[*]}
+    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="$TEST_THREADS_DEFAULT" "fw_cfg::$test_filter" -- ${test_binary_args[*]}
     RES=$?
 fi
 
 if [ $RES -eq 0 ]; then
     cargo build --features "mshv,ivshmem" --all --release --target "$BUILD_TARGET"
-    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads=$(($(nproc) / 4)) "ivshmem::$test_filter" -- ${test_binary_args[*]}
+    time cargo nextest run $test_features --retries 3 --no-fail-fast --no-tests=pass --test-threads="$TEST_THREADS_DEFAULT" "ivshmem::$test_filter" -- ${test_binary_args[*]}
     RES=$?
 fi