diff --git a/.kokoro/build.sh b/.kokoro/build.sh
index ecdd0a3ea514..1badebcebd69 100755
--- a/.kokoro/build.sh
+++ b/.kokoro/build.sh
@@ -360,16 +360,24 @@ case ${JOB_TYPE} in
 
 esac
 
-if [ "${REPORT_COVERAGE}" == "true" ]; then
-  bash ${KOKORO_GFILE_DIR}/codecov.sh
+if [[ "${REPORT_COVERAGE}" == "true" ]]; then
+  if [[ -n "${KOKORO_GFILE_DIR:-}" && -f "${KOKORO_GFILE_DIR:-}/codecov.sh" ]]; then
+    bash "${KOKORO_GFILE_DIR}/codecov.sh"
+  else
+    echo "Warning: REPORT_COVERAGE is true, but codecov.sh was not found in KOKORO_GFILE_DIR."
+  fi
 fi
 
 # fix output location of logs
 bash .kokoro/coerce_logs.sh
 
 if [[ "${ENABLE_FLAKYBOT}" == "true" ]]; then
-  chmod +x ${KOKORO_GFILE_DIR}/linux_amd64/flakybot
-  ${KOKORO_GFILE_DIR}/linux_amd64/flakybot -repo=googleapis/google-cloud-java
+  if [[ -n "${KOKORO_GFILE_DIR:-}" && -f "${KOKORO_GFILE_DIR:-}/linux_amd64/flakybot" ]]; then
+    chmod +x "${KOKORO_GFILE_DIR}/linux_amd64/flakybot" || true
+    "${KOKORO_GFILE_DIR}/linux_amd64/flakybot" -repo=googleapis/google-cloud-java
+  else
+    echo "Warning: ENABLE_FLAKYBOT is true, but flakybot binary was not found in KOKORO_GFILE_DIR."
+  fi
 fi
 
 echo "exiting with ${RETURN_CODE}"