diff --git a/src/runtime/runtime_avr.go b/src/runtime/runtime_avr.go
index 083b4561..09f91f7a 100644
--- a/src/runtime/runtime_avr.go
+++ b/src/runtime/runtime_avr.go
@@ -31,10 +31,10 @@ const (
 )
 
 //go:extern _sbss
-var _sbss unsafe.Pointer
+var _sbss [0]byte
 
 //go:extern _ebss
-var _ebss unsafe.Pointer
+var _ebss [0]byte
 
 //go:export main
 func main() {
@@ -49,8 +49,8 @@ func preinit() {
 	// Initialize .bss: zero-initialized global variables.
 	ptr := unsafe.Pointer(&_sbss)
 	for ptr != unsafe.Pointer(&_ebss) {
-		*(*uint32)(ptr) = 0
-		ptr = unsafe.Pointer(uintptr(ptr) + 4)
+		*(*uint8)(ptr) = 0
+		ptr = unsafe.Pointer(uintptr(ptr) + 1)
 	}
 }