diff --git a/firefox-ios/Client.xcodeproj/project.pbxproj b/firefox-ios/Client.xcodeproj/project.pbxproj
index 9afb3b5f16a2..0ad2c56371fb 100644
--- a/firefox-ios/Client.xcodeproj/project.pbxproj
+++ b/firefox-ios/Client.xcodeproj/project.pbxproj
@@ -26256,6 +26256,7 @@
 				SUPPORTED_PLATFORMS = "iphonesimulator iphoneos";
 				SWIFT_TREAT_WARNINGS_AS_ERRORS = YES;
 				SWIFT_UPCOMING_FEATURE_DEPRECATE_APPLICATION_MAIN = YES;
+				SWIFT_UPCOMING_FEATURE_FORWARD_TRAILING_CLOSURES = YES;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "iPhone, iPad";
 				TEST_TARGET_NAME = Client;
@@ -26731,6 +26732,7 @@
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = TESTING;
 				SWIFT_TREAT_WARNINGS_AS_ERRORS = YES;
 				SWIFT_UPCOMING_FEATURE_DEPRECATE_APPLICATION_MAIN = YES;
+				SWIFT_UPCOMING_FEATURE_FORWARD_TRAILING_CLOSURES = YES;
 				VALIDATE_WORKSPACE = YES;
 			};
 			name = Fennec_Testing;
@@ -27500,6 +27502,7 @@
 				);
 				SWIFT_TREAT_WARNINGS_AS_ERRORS = YES;
 				SWIFT_UPCOMING_FEATURE_DEPRECATE_APPLICATION_MAIN = YES;
+				SWIFT_UPCOMING_FEATURE_FORWARD_TRAILING_CLOSURES = YES;
 				VALIDATE_WORKSPACE = YES;
 			};
 			name = Firefox;
@@ -27785,6 +27788,7 @@
 				);
 				SWIFT_TREAT_WARNINGS_AS_ERRORS = YES;
 				SWIFT_UPCOMING_FEATURE_DEPRECATE_APPLICATION_MAIN = YES;
+				SWIFT_UPCOMING_FEATURE_FORWARD_TRAILING_CLOSURES = YES;
 				VALIDATE_WORKSPACE = YES;
 			};
 			name = Fennec_Enterprise;
@@ -28074,6 +28078,7 @@
 				);
 				SWIFT_TREAT_WARNINGS_AS_ERRORS = YES;
 				SWIFT_UPCOMING_FEATURE_DEPRECATE_APPLICATION_MAIN = YES;
+				SWIFT_UPCOMING_FEATURE_FORWARD_TRAILING_CLOSURES = YES;
 				VALIDATE_WORKSPACE = YES;
 			};
 			name = FirefoxBeta;
@@ -28583,6 +28588,7 @@
 				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
 				SWIFT_TREAT_WARNINGS_AS_ERRORS = YES;
 				SWIFT_UPCOMING_FEATURE_DEPRECATE_APPLICATION_MAIN = YES;
+				SWIFT_UPCOMING_FEATURE_FORWARD_TRAILING_CLOSURES = YES;
 				VALIDATE_WORKSPACE = YES;
 			};
 			name = Fennec;