diff --git a/boards/x86_64/intel64/qemu-intel64/configs/nsh/defconfig b/boards/x86_64/intel64/qemu-intel64/configs/nsh/defconfig
index ac4caa9bcc3..cc5f5d72ff1 100644
--- a/boards/x86_64/intel64/qemu-intel64/configs/nsh/defconfig
+++ b/boards/x86_64/intel64/qemu-intel64/configs/nsh/defconfig
@@ -57,4 +57,5 @@ CONFIG_START_YEAR=2011
 CONFIG_SYSTEM_NSH=y
 CONFIG_SYSTEM_TIME64=y
 CONFIG_TESTING_OSTEST=y
+CONFIG_TESTING_OSTEST_STACKSIZE=4194304
 CONFIG_USEC_PER_TICK=1
diff --git a/boards/x86_64/intel64/qemu-intel64/configs/ostest/defconfig b/boards/x86_64/intel64/qemu-intel64/configs/ostest/defconfig
index 4d682859e89..dcd95a1fe82 100644
--- a/boards/x86_64/intel64/qemu-intel64/configs/ostest/defconfig
+++ b/boards/x86_64/intel64/qemu-intel64/configs/ostest/defconfig
@@ -48,5 +48,5 @@ CONFIG_START_MONTH=3
 CONFIG_START_YEAR=2011
 CONFIG_SYSTEM_TIME64=y
 CONFIG_TESTING_OSTEST=y
-CONFIG_TESTING_OSTEST_STACKSIZE=4149304
+CONFIG_TESTING_OSTEST_STACKSIZE=4194304
 CONFIG_USEC_PER_TICK=1