diff --git a/ports/rp2/CMakeLists.txt b/ports/rp2/CMakeLists.txt
index 8c46a74e9..dc40d7e2d 100644
--- a/ports/rp2/CMakeLists.txt
+++ b/ports/rp2/CMakeLists.txt
@@ -556,8 +556,8 @@ target_compile_definitions(${MICROPY_TARGET} PRIVATE
     LFS1_NO_MALLOC LFS1_NO_DEBUG LFS1_NO_WARN LFS1_NO_ERROR LFS1_NO_ASSERT
     LFS2_NO_MALLOC LFS2_NO_DEBUG LFS2_NO_WARN LFS2_NO_ERROR LFS2_NO_ASSERT
     PICO_FLOAT_PROPAGATE_NANS=1
-    PICO_STACK_SIZE=0x2000
-    PICO_CORE1_STACK_SIZE=0
+    PICO_STACK_SIZE=0x1000
+    PICO_CORE1_STACK_SIZE=0x1000
     PICO_MAX_SHARED_IRQ_HANDLERS=8 # we need more than the default
     PICO_PROGRAM_NAME="MicroPython"
     PICO_NO_PROGRAM_VERSION_STRING=1 # do it ourselves in main.c