diff --git a/src/lparstat.c b/src/lparstat.c
index 9d9ba1b..30889b2 100644
--- a/src/lparstat.c
+++ b/src/lparstat.c
@@ -460,7 +460,8 @@ void get_cpu_app(struct sysentry *unused_se, char *buf)
 	se = get_sysentry("pool_idle_time");
 	new_app = strtoll(se->value, NULL, 0);
 	if (se->old_value[0] == '\0') {
-		old_app = 0;
+		se = get_sysentry("boot_pool_idle_time");
+		old_app = strtoll(se->value, NULL, 0);
 	} else {
 		old_app = strtoll(se->old_value, NULL, 0);
 	}
diff --git a/src/lparstat.h b/src/lparstat.h
index b7c88e9..77203e1 100644
--- a/src/lparstat.h
+++ b/src/lparstat.h
@@ -124,6 +124,8 @@ struct sysentry system_data[] = {
 	 .get = &get_percent_entry},
 	{.name = "pool_idle_time",
 	 .descr = "Shared Processor Pool Idle Time"},
+	{.name = "boot_pool_idle_time",
+	 .descr = "Shared Processor Pool Idle Time"},
 	{.name = "pool_num_procs",
 	 .descr = "Shared Processor Pool Processors"},
 	{.name = "unallocated_capacity_weight",