diff --git a/mk/sub.mk b/mk/sub.mk
index 1c155d6de09..266295d519a 100644
--- a/mk/sub.mk
+++ b/mk/sub.mk
@@ -83,10 +83,6 @@ DEPS_rust-css += \
 	rust-wapcaplet \
 	$(NULL)
 
-CFLAGS_mozjs += \
-	"-I../mozjs/dist/include" \
-	$(NULL)
-
 DEPS_rust-mozjs += \
 	mozjs \
 	$(NULL)
diff --git a/src/support/spidermonkey/mozjs b/src/support/spidermonkey/mozjs
index 50f2e99633b..15c494b9204 160000
--- a/src/support/spidermonkey/mozjs
+++ b/src/support/spidermonkey/mozjs
@@ -1 +1 @@
-Subproject commit 50f2e99633bf28f24b284821dbb723b38f2756e0
+Subproject commit 15c494b9204bb4ecdfbeab142c0ea01e5f0c9a1b