diff --git a/tests/dispatch_cascade.c b/tests/dispatch_cascade.c
index 78561ddd3..ad5a35911 100644
--- a/tests/dispatch_cascade.c
+++ b/tests/dispatch_cascade.c
@@ -79,7 +79,7 @@ histogram(void)
 		}
 	}
 
-	printf("maxcount = %ld\n", maxcount);
+	printf("maxcount = %zd\n", maxcount);
 
 	size_t x,y;
 	for (y = 20; y > 0; --y) {
diff --git a/tests/dispatch_io_net.c b/tests/dispatch_io_net.c
index bbffabc39..e35c744d5 100644
--- a/tests/dispatch_io_net.c
+++ b/tests/dispatch_io_net.c
@@ -277,7 +277,7 @@ main(int argc, char** argv)
 				// convenience method handlers should only be called once
 				if (remaining) {
 					fprintf(stderr, "Server-dispatch_write() incomplete .. "
-							"%lu bytes\n", dispatch_data_get_size(remaining));
+							"%zu bytes\n", dispatch_data_get_size(remaining));
 					close(read_fd);
 					close(clientfd);
 					close(sockfd);
diff --git a/tests/dispatch_starfish.c b/tests/dispatch_starfish.c
index 0fdbe892d..e5d3fab87 100644
--- a/tests/dispatch_starfish.c
+++ b/tests/dispatch_starfish.c
@@ -68,7 +68,7 @@ collect(void *context __attribute__((unused)))
 	math = delta;
 	math /= COUNT * COUNT * 2ul + COUNT * 2ul;
 
-	printf("lap: %ld\n", lap_count_down);
+	printf("lap: %zd\n", lap_count_down);
 	printf("count: %lu\n", COUNT);
 	printf("delta: %lu ns\n", delta);
 	printf("math: %Lf ns / lap\n", math);
@@ -144,7 +144,7 @@ do_test(void)
 	start = mach_absolute_time();
 
 	for (i = 0; i < COUNT; i++) {
-		snprintf(buf, sizeof(buf), "com.example.starfish-node#%ld", i);
+		snprintf(buf, sizeof(buf), "com.example.starfish-node#%zd", i);
 		queues[i] = dispatch_queue_create(buf, NULL);
 		dispatch_suspend(queues[i]);
 		dispatch_set_target_queue(queues[i], soup);