diff --git a/BUILD b/BUILD
index 50dba1e5e71..ec8bed94f53 100644
--- a/BUILD
+++ b/BUILD
@@ -229,7 +229,7 @@ python_config_settings()
 # This should be updated along with build_handwritten.yaml
 g_stands_for = "gnarly"  # @unused
 
-core_version = "41.0.0"  # @unused
+core_version = "42.0.0"  # @unused
 
 version = "1.65.0-dev"  # @unused
 
diff --git a/build_handwritten.yaml b/build_handwritten.yaml
index e9eac935968..33d07a997bf 100644
--- a/build_handwritten.yaml
+++ b/build_handwritten.yaml
@@ -12,7 +12,7 @@ settings:
   '#08': Use "-preN" suffixes to identify pre-release versions
   '#09': Per-language overrides are possible with (eg) ruby_version tag here
   '#10': See the expand_version.py for all the quirks here
-  core_version: 41.0.0
+  core_version: 42.0.0
   csharp_major_version: 2
   g_stands_for: gnarly
   protobuf_version: 3.26.1