diff --git a/src/modules/uORB/uORB.cpp b/src/modules/uORB/uORB.cpp
index cf32658673..4724502ebc 100644
--- a/src/modules/uORB/uORB.cpp
+++ b/src/modules/uORB/uORB.cpp
@@ -45,7 +45,7 @@ orb_advert_t orb_advertise(const struct orb_metadata *meta, const void *data)
 	return uORB::Manager::get_instance()->orb_advertise(meta, data);
 }
 
-orb_advert_t orb_advertise_queue(const struct orb_metadata *meta, const void *data, int queue_size)
+orb_advert_t orb_advertise_queue(const struct orb_metadata *meta, const void *data, unsigned int queue_size)
 {
 	return uORB::Manager::get_instance()->orb_advertise(meta, data, queue_size);
 }
@@ -57,7 +57,7 @@ orb_advert_t orb_advertise_multi(const struct orb_metadata *meta, const void *da
 }
 
 orb_advert_t orb_advertise_multi_queue(const struct orb_metadata *meta, const void *data, int *instance,
-				       int priority, int queue_size)
+				       int priority, unsigned int queue_size)
 {
 	return uORB::Manager::get_instance()->orb_advertise_multi(meta, data, instance, priority, queue_size);
 }
diff --git a/src/modules/uORB/uORB.h b/src/modules/uORB/uORB.h
index e189476f32..c1b03c0def 100644
--- a/src/modules/uORB/uORB.h
+++ b/src/modules/uORB/uORB.h
@@ -144,7 +144,7 @@ extern orb_advert_t orb_advertise(const struct orb_metadata *meta, const void *d
  * @see uORB::Manager::orb_advertise()
  */
 extern orb_advert_t orb_advertise_queue(const struct orb_metadata *meta, const void *data,
-					int queue_size) __EXPORT;
+					unsigned int queue_size) __EXPORT;
 
 /**
  * @see uORB::Manager::orb_advertise_multi()
@@ -156,7 +156,7 @@ extern orb_advert_t orb_advertise_multi(const struct orb_metadata *meta, const v
  * @see uORB::Manager::orb_advertise_multi()
  */
 extern orb_advert_t orb_advertise_multi_queue(const struct orb_metadata *meta, const void *data, int *instance,
-		int priority, int queue_size) __EXPORT;
+		int priority, unsigned int queue_size) __EXPORT;
 
 /**
  * @see uORB::Manager::orb_unadvertise()
diff --git a/src/modules/uORB/uORBManager.cpp b/src/modules/uORB/uORBManager.cpp
index 6c2309b13f..e5e669527a 100644
--- a/src/modules/uORB/uORBManager.cpp
+++ b/src/modules/uORB/uORBManager.cpp
@@ -87,14 +87,14 @@ int uORB::Manager::orb_exists(const struct orb_metadata *meta, int instance)
 #endif
 }
 
-orb_advert_t uORB::Manager::orb_advertise(const struct orb_metadata *meta, const void *data, int queue_size)
+orb_advert_t uORB::Manager::orb_advertise(const struct orb_metadata *meta, const void *data, unsigned int queue_size)
 {
 	//warnx("orb_advertise meta = %p", meta);
 	return orb_advertise_multi(meta, data, nullptr, ORB_PRIO_DEFAULT, queue_size);
 }
 
 orb_advert_t uORB::Manager::orb_advertise_multi(const struct orb_metadata *meta, const void *data, int *instance,
-		int priority, int queue_size)
+		int priority, unsigned int queue_size)
 {
 	int result, fd;
 	orb_advert_t advertiser;
diff --git a/src/modules/uORB/uORBManager.hpp b/src/modules/uORB/uORBManager.hpp
index 21f5777265..9a6a56c48a 100644
--- a/src/modules/uORB/uORBManager.hpp
+++ b/src/modules/uORB/uORBManager.hpp
@@ -104,7 +104,7 @@ public:
 	 *      ORB_DEFINE with no corresponding ORB_DECLARE)
 	 *      this function will return nullptr and set errno to ENOENT.
 	 */
-	orb_advert_t orb_advertise(const struct orb_metadata *meta, const void *data, int queue_size = 1);
+	orb_advert_t orb_advertise(const struct orb_metadata *meta, const void *data, unsigned int queue_size = 1);
 
 	/**
 	 * Advertise as the publisher of a topic.
@@ -141,7 +141,7 @@ public:
 	 *      this function will return -1 and set errno to ENOENT.
 	 */
 	orb_advert_t orb_advertise_multi(const struct orb_metadata *meta, const void *data, int *instance,
-					 int priority, int queue_size = 1) ;
+					 int priority, unsigned int queue_size = 1) ;
 
 
 	/**
diff --git a/src/modules/uORB/uORB_tests/uORBTest_UnitTest.cpp b/src/modules/uORB/uORB_tests/uORBTest_UnitTest.cpp
index eaa0221c60..7bcf9d7e4f 100644
--- a/src/modules/uORB/uORB_tests/uORBTest_UnitTest.cpp
+++ b/src/modules/uORB/uORB_tests/uORBTest_UnitTest.cpp
@@ -587,7 +587,7 @@ int uORBTest::UnitTest::test_queue()
 	}
 
 
-	const int queue_size = 11;
+	const unsigned int queue_size = 11;
 	t.val = 0;
 	ptopic = orb_advertise_queue(ORB_ID(orb_test_medium_queue), &t, queue_size);
 
@@ -635,12 +635,12 @@ int uORBTest::UnitTest::test_queue()
 
 	test_note("  Testing to write some elements...");
 
-	for (int i = 0; i < queue_size - 2; ++i) {
+	for (unsigned int i = 0; i < queue_size - 2; ++i) {
 		t.val = i;
 		orb_publish(ORB_ID(orb_test_medium_queue), ptopic, &t);
 	}
 
-	for (int i = 0; i < queue_size - 2; ++i) {
+	for (unsigned int i = 0; i < queue_size - 2; ++i) {
 		CHECK_UPDATED(i);
 		CHECK_COPY(u.val, i);
 	}
@@ -650,12 +650,12 @@ int uORBTest::UnitTest::test_queue()
 	test_note("  Testing overflow...");
 	int overflow_by = 3;
 
-	for (int i = 0; i < queue_size + overflow_by; ++i) {
+	for (unsigned int i = 0; i < queue_size + overflow_by; ++i) {
 		t.val = i;
 		orb_publish(ORB_ID(orb_test_medium_queue), ptopic, &t);
 	}
 
-	for (int i = 0; i < queue_size; ++i) {
+	for (unsigned int i = 0; i < queue_size; ++i) {
 		CHECK_UPDATED(i);
 		CHECK_COPY(u.val, i + overflow_by);
 	}
@@ -664,7 +664,7 @@ int uORBTest::UnitTest::test_queue()
 
 	test_note("  Testing underflow...");
 
-	for (int i = 0; i < queue_size; ++i) {
+	for (unsigned int i = 0; i < queue_size; ++i) {
 		CHECK_NOT_UPDATED(i);
 		CHECK_COPY(u.val, queue_size + overflow_by - 1);
 	}
@@ -694,7 +694,7 @@ int uORBTest::UnitTest::pub_test_queue_main()
 {
 	struct orb_test_medium t;
 	orb_advert_t ptopic;
-	const int queue_size = 50;
+	const unsigned int queue_size = 50;
 	t.val = 0;
 
 	if ((ptopic = orb_advertise_queue(ORB_ID(orb_test_medium_queue_poll), &t, queue_size)) == nullptr) {