diff --git a/src/kernel/boot/loader/heap.cpp b/src/kernel/boot/loader/heap.cpp
index fc11fdd08c..e9c12ae04a 100644
--- a/src/kernel/boot/loader/heap.cpp
+++ b/src/kernel/boot/loader/heap.cpp
@@ -234,7 +234,7 @@ dump_chunks(void)
 }
 #endif
 
-int32
+uint32
 heap_available(void)
 {
 	return sAvailable;