diff --git a/antlir/bzl/linux/systemd/service_unit.jinja2 b/antlir/bzl/linux/systemd/service_unit.jinja2
index 2a92273ae24..ca2a8218142 100644
--- a/antlir/bzl/linux/systemd/service_unit.jinja2
+++ b/antlir/bzl/linux/systemd/service_unit.jinja2
@@ -12,7 +12,9 @@ EnvironmentFile={{ environment_file }}
 {% for cmd in exec_start %}
 ExecStart={{ cmd }}
 {% endfor %}
-TimeoutStartSec=15min
+{% if timeout_start %}
+TimeoutStartSec={{ timeout_start }}
+{% endif %}
 TimeoutStopSec=90s
 {% for key, val in environment.items() %}
 Environment={{ key }}={{ val }}
diff --git a/antlir/bzl/linux/systemd/systemd.shape.bzl b/antlir/bzl/linux/systemd/systemd.shape.bzl
index 9f2b289a0c3..b7257cc3875 100644
--- a/antlir/bzl/linux/systemd/systemd.shape.bzl
+++ b/antlir/bzl/linux/systemd/systemd.shape.bzl
@@ -22,6 +22,7 @@ service_t = shape.shape(
     environment = shape.field(shape.dict(str, str), optional = True),
     exec_start = shape.field(shape.list(str), optional = True),
     standard_output = shape.field(str, optional = True),
+    timeout_start = shape.field(str, optional = True),
 )
 
 timer_t = shape.shape(