diff --git a/packages/playwright-core/src/utils/isomorphic/stringUtils.ts b/packages/playwright-core/src/utils/isomorphic/stringUtils.ts
index 05f4d1dbcf..e612e2d1ef 100644
--- a/packages/playwright-core/src/utils/isomorphic/stringUtils.ts
+++ b/packages/playwright-core/src/utils/isomorphic/stringUtils.ts
@@ -36,7 +36,8 @@ export function toTitleCase(name: string) {
 }
 
 export function toSnakeCase(name: string): string {
-  return name.replace(/([a-z0-9])([A-Z])/g, '$1_$2').toLowerCase();
+  // E.g. ignoreHTTPSErrors => ignore_https_errors.
+  return name.replace(/([a-z0-9])([A-Z])/g, '$1_$2').replace(/([A-Z])([A-Z][a-z])/g, '$1_$2').toLowerCase();
 }
 
 export function cssEscape(s: string): string {