diff --git a/pkg/rclgo/action.go b/pkg/rclgo/action.go
index 4d72b82..d4cb063 100644
--- a/pkg/rclgo/action.go
+++ b/pkg/rclgo/action.go
@@ -11,7 +11,6 @@ import (
 	"crypto/rand"
 	"errors"
 	"fmt"
-	"reflect"
 	"runtime"
 	"strings"
 	"sync"
@@ -349,7 +348,7 @@ func (n *Node) NewActionServer(
 	rclOpts := C.rcl_action_server_options_t{
 		allocator: *n.context.rcl_allocator_t,
 		result_timeout: C.rcl_duration_t{
-			nanoseconds: C.long(opts.ResultTimeout),
+			nanoseconds: C.int64_t(opts.ResultTimeout),
 		},
 	}
 	opts.GoalServiceQos.asCStruct(&rclOpts.goal_service_qos)
@@ -526,7 +525,6 @@ func (s *ActionServer) scheduleRemoval() {
 func (s *ActionServer) expireGoals() error {
 	var numExpired C.size_t
 	expiredGoals := make([]C.rcl_action_goal_info_t, 10)
-	expiredGoalsHeader := (*reflect.SliceHeader)(unsafe.Pointer(&expiredGoals))
 	s.rclServerMu.Lock()
 	defer s.rclServerMu.Unlock()
 	s.goalsMu.Lock()
@@ -534,8 +532,8 @@ func (s *ActionServer) expireGoals() error {
 	for {
 		rc := C.rcl_action_expire_goals(
 			&s.rclServer,
-			(*C.rcl_action_goal_info_t)(unsafe.Pointer(expiredGoalsHeader.Data)),
-			C.ulong(expiredGoalsHeader.Len),
+			unsafe.SliceData(expiredGoals),
+			C.size_t(len(expiredGoals)),
 			&numExpired,
 		)
 		if rc != C.RCL_RET_OK {
@@ -983,8 +981,8 @@ func (c *ActionClient) SendGoalRequest(ctx context.Context, request types.Messag
 	return resp, err
 }
 
-func (c *ActionClient) sendGoalRequest(req unsafe.Pointer) (C.long, error) {
-	var seqNum C.long
+func (c *ActionClient) sendGoalRequest(req unsafe.Pointer) (C.int64_t, error) {
+	var seqNum C.int64_t
 	rc := C.rcl_action_send_goal_request(&c.rclClient, req, &seqNum)
 	if rc != C.RCL_RET_OK {
 		return 0, errorsCastC(rc, "failed to send goal request")
@@ -992,7 +990,7 @@ func (c *ActionClient) sendGoalRequest(req unsafe.Pointer) (C.long, error) {
 	return seqNum, nil
 }
 
-func (c *ActionClient) takeGoalResponse(resp unsafe.Pointer) (C.long, interface{}, error) {
+func (c *ActionClient) takeGoalResponse(resp unsafe.Pointer) (C.int64_t, interface{}, error) {
 	var header C.rmw_request_id_t
 	switch rc := C.rcl_action_take_goal_response(&c.rclClient, &header, resp); rc {
 	case C.RCL_RET_OK:
@@ -1017,8 +1015,8 @@ func (c *ActionClient) GetResult(ctx context.Context, goalID *types.GoalID) (typ
 	return resp, err
 }
 
-func (c *ActionClient) sendResultRequest(req unsafe.Pointer) (C.long, error) {
-	var seqNum C.long
+func (c *ActionClient) sendResultRequest(req unsafe.Pointer) (C.int64_t, error) {
+	var seqNum C.int64_t
 	rc := C.rcl_action_send_result_request(&c.rclClient, req, &seqNum)
 	if rc != C.RCL_RET_OK {
 		return 0, errorsCastC(rc, "failed to send result request")
@@ -1026,7 +1024,7 @@ func (c *ActionClient) sendResultRequest(req unsafe.Pointer) (C.long, error) {
 	return seqNum, nil
 }
 
-func (c *ActionClient) takeResultResponse(resp unsafe.Pointer) (C.long, interface{}, error) {
+func (c *ActionClient) takeResultResponse(resp unsafe.Pointer) (C.int64_t, interface{}, error) {
 	var header C.rmw_request_id_t
 	switch rc := C.rcl_action_take_result_response(&c.rclClient, &header, resp); rc {
 	case C.RCL_RET_OK:
@@ -1060,8 +1058,8 @@ func (c *ActionClient) CancelGoal(ctx context.Context, request types.Message) (t
 	return resp, err
 }
 
-func (c *ActionClient) sendCancelRequest(req unsafe.Pointer) (C.long, error) {
-	var seqNum C.long
+func (c *ActionClient) sendCancelRequest(req unsafe.Pointer) (C.int64_t, error) {
+	var seqNum C.int64_t
 	rc := C.rcl_action_send_cancel_request(&c.rclClient, req, &seqNum)
 	if rc != C.RCL_RET_OK {
 		return 0, errorsCastC(rc, "failed to send cancel request")
@@ -1069,7 +1067,7 @@ func (c *ActionClient) sendCancelRequest(req unsafe.Pointer) (C.long, error) {
 	return seqNum, nil
 }
 
-func (c *ActionClient) takeCancelResponse(resp unsafe.Pointer) (C.long, interface{}, error) {
+func (c *ActionClient) takeCancelResponse(resp unsafe.Pointer) (C.int64_t, interface{}, error) {
 	var header C.rmw_request_id_t
 	switch rc := C.rcl_action_take_cancel_response(&c.rclClient, &header, resp); rc {
 	case C.RCL_RET_OK:
diff --git a/pkg/rclgo/logging.go b/pkg/rclgo/logging.go
index 32824d8..5e2afda 100644
--- a/pkg/rclgo/logging.go
+++ b/pkg/rclgo/logging.go
@@ -144,7 +144,7 @@ func logNamed(level LogSeverity, name, msg string) error {
 		}
 		loc.file_name = C.CString(file)
 		defer C.free(unsafe.Pointer(loc.file_name))
-		loc.line_number = C.ulong(line)
+		loc.line_number = C.size_t(line)
 	}
 	cname := C.CString(name)
 	defer C.free(unsafe.Pointer(cname))
diff --git a/pkg/rclgo/qos.go b/pkg/rclgo/qos.go
index 28b7528..409b10b 100644
--- a/pkg/rclgo/qos.go
+++ b/pkg/rclgo/qos.go
@@ -95,13 +95,13 @@ func NewDefaultServiceQosProfile() QosProfile {
 
 func (p *QosProfile) asCStruct(dst *C.rmw_qos_profile_t) {
 	dst.history = uint32(p.History)
-	dst.depth = C.ulong(p.Depth)
+	dst.depth = C.size_t(p.Depth)
 	dst.reliability = uint32(p.Reliability)
 	dst.durability = uint32(p.Durability)
-	dst.deadline = C.rmw_time_t{nsec: C.ulong(p.Deadline)}
-	dst.lifespan = C.rmw_time_t{nsec: C.ulong(p.Lifespan)}
+	dst.deadline = C.rmw_time_t{nsec: C.uint64_t(p.Deadline)}
+	dst.lifespan = C.rmw_time_t{nsec: C.uint64_t(p.Lifespan)}
 	dst.liveliness = uint32(p.Liveliness)
-	dst.liveliness_lease_duration = C.rmw_time_t{nsec: C.ulong(p.LivelinessLeaseDuration)}
+	dst.liveliness_lease_duration = C.rmw_time_t{nsec: C.uint64_t(p.LivelinessLeaseDuration)}
 	dst.avoid_ros_namespace_conventions = C.bool(p.AvoidRosNamespaceConventions)
 }
 
diff --git a/pkg/rclgo/rcl.go b/pkg/rclgo/rcl.go
index 9a55e14..f41feab 100644
--- a/pkg/rclgo/rcl.go
+++ b/pkg/rclgo/rcl.go
@@ -607,7 +607,7 @@ func (c *Context) NewTimer(timeout time.Duration, timer_callback func(*Timer)) (
 		timer.rcl_timer_t,
 		c.Clock().rcl_clock_t,
 		c.rcl_context_t,
-		(C.long)(timeout),
+		C.int64_t(timeout),
 		nil,
 		*c.rcl_allocator_t,
 	)
@@ -1072,8 +1072,8 @@ func (c *Client) Send(ctx context.Context, req types.Message) (types.Message, *S
 	return resp, nil, err
 }
 
-func (c *Client) sendRequest(req unsafe.Pointer) (C.long, error) {
-	var seqNum C.long
+func (c *Client) sendRequest(req unsafe.Pointer) (C.int64_t, error) {
+	var seqNum C.int64_t
 	rc := C.rcl_send_request(c.rclClient, req, &seqNum)
 	if rc != C.RCL_RET_OK {
 		return 0, errorsCastC(rc, "failed to send request")
@@ -1081,7 +1081,7 @@ func (c *Client) sendRequest(req unsafe.Pointer) (C.long, error) {
 	return seqNum, nil
 }
 
-func (c *Client) takeResponse(resp unsafe.Pointer) (C.long, interface{}, error) {
+func (c *Client) takeResponse(resp unsafe.Pointer) (C.int64_t, interface{}, error) {
 	var header C.rmw_service_info_t
 	switch rc := C.rcl_take_response_with_info(c.rclClient, &header, resp); rc {
 	case C.RCL_RET_OK:
@@ -1105,22 +1105,22 @@ type sendResult struct {
 }
 
 type requestSenderTransport struct {
-	SendRequest  func(unsafe.Pointer) (C.long, error)
-	TakeResponse func(unsafe.Pointer) (C.long, interface{}, error)
+	SendRequest  func(unsafe.Pointer) (C.int64_t, error)
+	TakeResponse func(unsafe.Pointer) (C.int64_t, interface{}, error)
 	TypeSupport  types.ServiceTypeSupport
 	Logger       *Logger
 }
 
 type requestSender struct {
 	transport       requestSenderTransport
-	pendingRequests map[C.long]chan *sendResult
+	pendingRequests map[C.int64_t]chan *sendResult
 	mutex           sync.Mutex
 }
 
 func newRequestSender(transport requestSenderTransport) requestSender {
 	return requestSender{
 		transport:       transport,
-		pendingRequests: make(map[C.long]chan *sendResult),
+		pendingRequests: make(map[C.int64_t]chan *sendResult),
 	}
 }
 
@@ -1155,7 +1155,7 @@ func (s *requestSender) Send(ctx context.Context, req types.Message) (types.Mess
 	}
 }
 
-func (s *requestSender) addPendingRequest(req types.Message) (<-chan *sendResult, C.long, error) {
+func (s *requestSender) addPendingRequest(req types.Message) (<-chan *sendResult, C.int64_t, error) {
 	ts := s.transport.TypeSupport.Request()
 	buf := ts.PrepareMemory()
 	defer ts.ReleaseMemory(buf)