diff --git a/samples/subsys/mgmt/mcumgr/smp_svr/prj.conf b/samples/subsys/mgmt/mcumgr/smp_svr/prj.conf
index 06a27644bacb24..b276ec570f932c 100644
--- a/samples/subsys/mgmt/mcumgr/smp_svr/prj.conf
+++ b/samples/subsys/mgmt/mcumgr/smp_svr/prj.conf
@@ -10,6 +10,9 @@ CONFIG_FLASH_MAP=y
 CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2304
 CONFIG_MAIN_STACK_SIZE=2048
 
+# Enable support for both small and big heaps.
+CONFIG_SYS_HEAP_AUTO=y
+
 # Ensure an MCUboot-compatible binary is generated.
 CONFIG_BOOTLOADER_MCUBOOT=y