diff --git a/boards/x86_64/intel64/qemu-intel64/configs/ostest/defconfig b/boards/x86_64/intel64/qemu-intel64/configs/ostest/defconfig
index 66e9f33ef2877..ed0585683f212 100644
--- a/boards/x86_64/intel64/qemu-intel64/configs/ostest/defconfig
+++ b/boards/x86_64/intel64/qemu-intel64/configs/ostest/defconfig
@@ -48,4 +48,5 @@ CONFIG_START_MONTH=3
 CONFIG_START_YEAR=2011
 CONFIG_SYSTEM_TIME64=y
 CONFIG_TESTING_OSTEST=y
+CONFIG_TESTING_OSTEST_STACKSIZE=4194304
 CONFIG_USEC_PER_TICK=1