diff --git a/esp-riscv-rt/src/lib.rs b/esp-riscv-rt/src/lib.rs
index a7f344327..4808cefd3 100644
--- a/esp-riscv-rt/src/lib.rs
+++ b/esp-riscv-rt/src/lib.rs
@@ -721,12 +721,12 @@ r#"
     "#,
     // store current priority, set threshold, enable interrupts
     r#"
-    addi sp, sp, -4 #build stack
+    addi sp, sp, -16 #build stack
     sw ra, 0(sp)
     jal ra, _handle_priority
     lw ra, 0(sp)
     sw a0, 0(sp) #reuse old stack, a0 is return of _handle_priority
-    addi a0, sp, 4 #the proper stack pointer is an argument to the HAL handler
+    addi a0, sp, 16 #the proper stack pointer is an argument to the HAL handler
     "#,
     // jump to handler loaded in direct handler
     r#"
@@ -736,7 +736,7 @@ r#"
     r#"
     lw a0, 0(sp) #load stored priority
     jal ra, _restore_priority
-    addi sp, sp, 4 #pop
+    addi sp, sp, 16 #pop
     "#,
     r#"
     lw t1, 31*4(sp)