diff --git a/library/bdwgc/build.rs b/library/bdwgc/build.rs
index d49e286edcf52..d95da26bfd721 100644
--- a/library/bdwgc/build.rs
+++ b/library/bdwgc/build.rs
@@ -32,7 +32,6 @@ fn main() {
         .pic(true)
         .define("BUILD_SHARED_LIBS", "OFF")
         .cflag("-DGC_ALWAYS_MULTITHREADED")
-        .cflag("-DDISCLAIM_MARK_CHILDREN")
         .cflag("-DBUFFERED_FINALIZATION")
         .cflag("-DGC_JAVA_FINALIZATION");
 
diff --git a/src/bdwgc b/src/bdwgc
index be14dd1e8ee84..5f21e15f028cf 160000
--- a/src/bdwgc
+++ b/src/bdwgc
@@ -1 +1 @@
-Subproject commit be14dd1e8ee84ef93b1a7eec565ea79b10fc3a9c
+Subproject commit 5f21e15f028cf92cdbcfc659b76fb9efe78fbd1c