diff --git a/src/runtime/runtime_avr.go b/src/runtime/runtime_avr.go
index 78c6c41c..083b4561 100644
--- a/src/runtime/runtime_avr.go
+++ b/src/runtime/runtime_avr.go
@@ -47,10 +47,10 @@ func main() {
 
 func preinit() {
 	// Initialize .bss: zero-initialized global variables.
-	ptr := uintptr(unsafe.Pointer(&_sbss))
-	for ptr != uintptr(unsafe.Pointer(&_ebss)) {
-		*(*uint8)(unsafe.Pointer(ptr)) = 0
-		ptr += 1
+	ptr := unsafe.Pointer(&_sbss)
+	for ptr != unsafe.Pointer(&_ebss) {
+		*(*uint32)(ptr) = 0
+		ptr = unsafe.Pointer(uintptr(ptr) + 4)
 	}
 }
 
diff --git a/src/runtime/runtime_cortexm.go b/src/runtime/runtime_cortexm.go
index 909206e9..e6b5d294 100644
--- a/src/runtime/runtime_cortexm.go
+++ b/src/runtime/runtime_cortexm.go
@@ -24,19 +24,19 @@ var _edata unsafe.Pointer
 
 func preinit() {
 	// Initialize .bss: zero-initialized global variables.
-	ptr := uintptr(unsafe.Pointer(&_sbss))
-	for ptr != uintptr(unsafe.Pointer(&_ebss)) {
-		*(*uint32)(unsafe.Pointer(ptr)) = 0
-		ptr += 4
+	ptr := unsafe.Pointer(&_sbss)
+	for ptr != unsafe.Pointer(&_ebss) {
+		*(*uint32)(ptr) = 0
+		ptr = unsafe.Pointer(uintptr(ptr) + 4)
 	}
 
 	// Initialize .data: global variables initialized from flash.
-	src := uintptr(unsafe.Pointer(&_sidata))
-	dst := uintptr(unsafe.Pointer(&_sdata))
-	for dst != uintptr(unsafe.Pointer(&_edata)) {
-		*(*uint32)(unsafe.Pointer(dst)) = *(*uint32)(unsafe.Pointer(src))
-		dst += 4
-		src += 4
+	src := unsafe.Pointer(&_sidata)
+	dst := unsafe.Pointer(&_sdata)
+	for dst != unsafe.Pointer(&_edata) {
+		*(*uint32)(dst) = *(*uint32)(src)
+		dst = unsafe.Pointer(uintptr(dst) + 4)
+		src = unsafe.Pointer(uintptr(src) + 4)
 	}
 }
 
diff --git a/src/runtime/runtime_fe310.go b/src/runtime/runtime_fe310.go
index ded5edde..6516877e 100644
--- a/src/runtime/runtime_fe310.go
+++ b/src/runtime/runtime_fe310.go
@@ -62,19 +62,19 @@ func pric_init() {
 
 func preinit() {
 	// Initialize .bss: zero-initialized global variables.
-	ptr := uintptr(unsafe.Pointer(&_sbss))
-	for ptr != uintptr(unsafe.Pointer(&_ebss)) {
-		*(*uint32)(unsafe.Pointer(ptr)) = 0
-		ptr += 4
+	ptr := unsafe.Pointer(&_sbss)
+	for ptr != unsafe.Pointer(&_ebss) {
+		*(*uint32)(ptr) = 0
+		ptr = unsafe.Pointer(uintptr(ptr) + 4)
 	}
 
 	// Initialize .data: global variables initialized from flash.
-	src := uintptr(unsafe.Pointer(&_sidata))
-	dst := uintptr(unsafe.Pointer(&_sdata))
-	for dst != uintptr(unsafe.Pointer(&_edata)) {
-		*(*uint32)(unsafe.Pointer(dst)) = *(*uint32)(unsafe.Pointer(src))
-		dst += 4
-		src += 4
+	src := unsafe.Pointer(&_sidata)
+	dst := unsafe.Pointer(&_sdata)
+	for dst != unsafe.Pointer(&_edata) {
+		*(*uint32)(dst) = *(*uint32)(src)
+		dst = unsafe.Pointer(uintptr(dst) + 4)
+		src = unsafe.Pointer(uintptr(src) + 4)
 	}
 }