diff --git a/ports/rp2/CMakeLists.txt b/ports/rp2/CMakeLists.txt
index ad5fb6026..dd14bac8e 100644
--- a/ports/rp2/CMakeLists.txt
+++ b/ports/rp2/CMakeLists.txt
@@ -569,8 +569,8 @@ 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=0x1000
-    PICO_CORE1_STACK_SIZE=0x1000
+    PICO_STACK_SIZE=0x1800
+    PICO_CORE1_STACK_SIZE=0x800
     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
diff --git a/ports/rp2/memmap_mp_rp2040.ld b/ports/rp2/memmap_mp_rp2040.ld
index ec047c8be..7de7188f5 100644
--- a/ports/rp2/memmap_mp_rp2040.ld
+++ b/ports/rp2/memmap_mp_rp2040.ld
@@ -250,7 +250,7 @@ SECTIONS
     __GcHeapEnd = ORIGIN(RAM) + LENGTH(RAM);
 
     /* Define memory for the C stack */
-    __StackOneTop = ORIGIN(SCRATCH_X) + LENGTH(SCRATCH_X);
+    __StackOneTop = ORIGIN(SCRATCH_X) + SIZEOF(.stack1_dummy);
     __StackTop = ORIGIN(SCRATCH_Y) + LENGTH(SCRATCH_Y);
     __StackOneBottom = __StackOneTop - SIZEOF(.stack1_dummy);
     __StackBottom = __StackTop - SIZEOF(.stack_dummy);