diff --git a/common.gypi b/common.gypi
index 70569b3e3fe785..d1e24c52d81be0 100644
--- a/common.gypi
+++ b/common.gypi
@@ -36,7 +36,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.14',
+    'v8_embedder_string': '-node.15',
 
     ##### V8 defaults for Node.js #####
 
diff --git a/deps/v8/src/common/checks.h b/deps/v8/src/common/checks.h
index 59c845b4f549ff..33d7a8458bd95f 100644
--- a/deps/v8/src/common/checks.h
+++ b/deps/v8/src/common/checks.h
@@ -15,7 +15,7 @@
 
 #ifdef ENABLE_SLOW_DCHECKS
 #define SLOW_DCHECK(condition) \
-  CHECK(!v8::internal::FLAG_enable_slow_asserts || (condition))
+  CHECK(!v8::internal::v8_flags.enable_slow_asserts.value() || (condition))
 #define SLOW_DCHECK_IMPLIES(lhs, rhs) SLOW_DCHECK(!(lhs) || (rhs))
 #else
 #define SLOW_DCHECK(condition) ((void)0)