diff --git a/build/bash/common.inc b/build/bash/common.inc
index dd70247..821da0c 100644
--- a/build/bash/common.inc
+++ b/build/bash/common.inc
@@ -49,6 +49,12 @@
 	return $?
 }
 
+# Returns true if the environment contains Jenkins build variables.
+function is_jenkins_build() {
+	[ -v JENKINS_HOME ]
+	return $?
+}
+
 # Returns true if the `.repo_manifest` folder exists. The folder should contain
 # the manifest and be present in all Repo builds. Eventually this should be
 # obsolete as we switch exclusively to Repo.
diff --git a/kokoro/build.sh b/kokoro/build.sh
index 3108f05..0105980 100755
--- a/kokoro/build.sh
+++ b/kokoro/build.sh
@@ -20,7 +20,7 @@
 init_build
 
 # Assign default values to variables.
-if is_kokoro_build
+if is_kokoro_build || is_jenkins_build
 then
 	# Default config for Kokoro builds.
 	default_value HAFNIUM_HERMETIC_BUILD true