diff --git a/.travis.yml b/.travis.yml
index 85c8433..27bd1b9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -266,7 +266,7 @@ install:
   - git submodule init libs/type_traits
   - git submodule init tools/build
   - git submodule init tools/boost_install
-  - git submodule update
+  - git submodule update --jobs 4
   - cp -r $TRAVIS_BUILD_DIR/* libs/core
   - ./bootstrap.sh
   - ./b2 headers
diff --git a/appveyor.yml b/appveyor.yml
index a007db8..3664a15 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -63,7 +63,7 @@ install:
   - git submodule init libs/type_traits
   - git submodule init tools/build
   - git submodule init tools/boost_install
-  - git submodule update
+  - git submodule update --jobs 4
   - xcopy /s /e /q %APPVEYOR_BUILD_FOLDER% libs\core
   - cmd /c bootstrap
   - b2 headers