diff --git a/lib/configure.js b/lib/configure.js
index eae5700dd4..563af2c185 100644
--- a/lib/configure.js
+++ b/lib/configure.js
@@ -115,9 +115,11 @@ function configure (gyp, argv, callback) {
 
     log.verbose('build/' + configFilename, 'creating config file')
 
-    var config = process.config || {}
-      , defaults = config.target_defaults
-      , variables = config.variables
+    // In Node v19 process.config is now frozen, so we need to clone it
+    var config = JSON.parse(JSON.stringify(process.config || {}))
+
+    var defaults = config.target_defaults
+    var variables = config.variables
 
     // default "config.variables"
     if (!variables) variables = config.variables = {}