diff --git a/tools/internal_ci/linux/psm-interop-install-lib.sh b/tools/internal_ci/linux/psm-interop-install-lib.sh
new file mode 100755
index 00000000000..8b92344e392
--- /dev/null
+++ b/tools/internal_ci/linux/psm-interop-install-lib.sh
@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+# Copyright 2024 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+set -eo pipefail
+
+# Used locally.
+readonly TEST_DRIVER_INSTALL_SCRIPT_URL="https://raw.githubusercontent.com/${TEST_DRIVER_REPO_OWNER:-grpc}/psm-interop/${TEST_DRIVER_BRANCH:-main}/.kokoro/psm_interop_kokoro_lib.sh"
+
+psm::lang::source_install_lib() {
+  echo "Sourcing test driver install script from: ${TEST_DRIVER_INSTALL_SCRIPT_URL}"
+  local install_lib
+  # Download to a tmp file.
+  install_lib="$(mktemp -d)/psm_interop_kokoro_lib.sh"
+  curl -s --retry-connrefused --retry 5 -o "${install_lib}" "${TEST_DRIVER_INSTALL_SCRIPT_URL}"
+  # Checksum.
+  if command -v sha256sum &> /dev/null; then
+    echo "Install script checksum:"
+    sha256sum "${install_lib}"
+  fi
+  source "${install_lib}"
+}
diff --git a/tools/internal_ci/linux/psm-interop-test-cpp.sh b/tools/internal_ci/linux/psm-interop-test-cpp.sh
index 649470d8a33..8774b81b245 100755
--- a/tools/internal_ci/linux/psm-interop-test-cpp.sh
+++ b/tools/internal_ci/linux/psm-interop-test-cpp.sh
@@ -18,23 +18,7 @@ set -eo pipefail
 readonly GRPC_LANGUAGE="cpp"
 readonly BUILD_SCRIPT_DIR="$(dirname "$0")"
 
-# Used locally.
-readonly TEST_DRIVER_INSTALL_SCRIPT_URL="https://raw.githubusercontent.com/${TEST_DRIVER_REPO_OWNER:-grpc}/psm-interop/${TEST_DRIVER_BRANCH:-main}/.kokoro/psm_interop_kokoro_lib.sh"
-
-psm::lang::source_install_lib() {
-  echo "Sourcing test driver install script from: ${TEST_DRIVER_INSTALL_SCRIPT_URL}"
-  local install_lib
-  # Download to a tmp file.
-  install_lib="$(mktemp -d)/psm_interop_kokoro_lib.sh"
-  curl -s --retry-connrefused --retry 5 -o "${install_lib}" "${TEST_DRIVER_INSTALL_SCRIPT_URL}"
-  # Checksum.
-  if command -v sha256sum &> /dev/null; then
-    echo "Install script checksum:"
-    sha256sum "${install_lib}"
-  fi
-  source "${install_lib}"
-}
-
+source "${BUILD_SCRIPT_DIR}/psm-interop-install-lib.sh"
 psm::lang::source_install_lib
 source "${BUILD_SCRIPT_DIR}/psm-interop-build-${GRPC_LANGUAGE}.sh"
 psm::run "${PSM_TEST_SUITE}"
diff --git a/tools/internal_ci/linux/psm-interop-test-python.sh b/tools/internal_ci/linux/psm-interop-test-python.sh
index 74cf807cca8..3b804946389 100755
--- a/tools/internal_ci/linux/psm-interop-test-python.sh
+++ b/tools/internal_ci/linux/psm-interop-test-python.sh
@@ -18,23 +18,7 @@ set -eo pipefail
 readonly GRPC_LANGUAGE="python"
 readonly BUILD_SCRIPT_DIR="$(dirname "$0")"
 
-# Used locally.
-readonly TEST_DRIVER_INSTALL_SCRIPT_URL="https://raw.githubusercontent.com/${TEST_DRIVER_REPO_OWNER:-grpc}/psm-interop/${TEST_DRIVER_BRANCH:-main}/.kokoro/psm_interop_kokoro_lib.sh"
-
-psm::lang::source_install_lib() {
-  echo "Sourcing test driver install script from: ${TEST_DRIVER_INSTALL_SCRIPT_URL}"
-  local install_lib
-  # Download to a tmp file.
-  install_lib="$(mktemp -d)/psm_interop_kokoro_lib.sh"
-  curl -s --retry-connrefused --retry 5 -o "${install_lib}" "${TEST_DRIVER_INSTALL_SCRIPT_URL}"
-  # Checksum.
-  if command -v sha256sum &> /dev/null; then
-    echo "Install script checksum:"
-    sha256sum "${install_lib}"
-  fi
-  source "${install_lib}"
-}
-
+source "${BUILD_SCRIPT_DIR}/psm-interop-install-lib.sh"
 psm::lang::source_install_lib
 source "${BUILD_SCRIPT_DIR}/psm-interop-build-${GRPC_LANGUAGE}.sh"
 psm::run "${PSM_TEST_SUITE}"