diff --git a/src/trace.c b/src/trace.c
index b3d59d39..bf088133 100644
--- a/src/trace.c
+++ b/src/trace.c
@@ -341,7 +341,7 @@ char* tf_trace_export(tf_trace_t* trace)
 		size += snprintf(buffer + size, k_buffer_size - size,
 			"{\"ph\":\"M\",\"pid\":%d,\"tid\":\"0x%" PRIx64 "\",\"name\":\"thread_name\",\"args\":{\"name\":\"%s\"}},\n",
 			getpid(),
-			thread->id,
+			(uint64_t)thread->id,
 			thread->name);
 	}
 	uv_rwlock_rdunlock(&trace->threads_lock);