diff --git a/libcxx/utils/ci/run-buildbot b/libcxx/utils/ci/run-buildbot
--- a/libcxx/utils/ci/run-buildbot
+++ b/libcxx/utils/ci/run-buildbot
@@ -84,7 +84,7 @@
           -DCMAKE_BUILD_TYPE=RelWithDebInfo \
           -DCMAKE_INSTALL_PREFIX="${INSTALL_DIR}" \
           -DLIBCXX_ENABLE_WERROR=YES \
-          -DLLVM_LIT_ARGS="-sv --show-unsupported --xunit-xml-output test-results.xml" \
+          -DLLVM_LIT_ARGS="-sv --show-unsupported --xunit-xml-output test-results.xml --timeout=300" \
           "${@}"
 }
 
@@ -486,7 +486,7 @@
           -GNinja -DCMAKE_MAKE_PROGRAM="${NINJA}" \
           -DCMAKE_BUILD_TYPE=RelWithDebInfo \
           -DCMAKE_INSTALL_PREFIX="${INSTALL_DIR}" \
-          -DLLVM_LIT_ARGS="-sv --show-unsupported --xunit-xml-output test-results.xml" \
+          -DLLVM_LIT_ARGS="-sv --show-unsupported --xunit-xml-output test-results.xml --timeout=300" \
           -DLIBCXX_CXX_ABI=libcxxabi
     check-runtimes
 ;;