diff --git a/Config/Project.xcconfig b/Config/Project.xcconfig
index e8755a1264..cd17768992 100644
--- a/Config/Project.xcconfig
+++ b/Config/Project.xcconfig
@@ -6,7 +6,6 @@
 GCC_TREAT_INCOMPATIBLE_POINTER_TYPE_WARNINGS_AS_ERRORS = YES
 GCC_TREAT_WARNINGS_AS_ERRORS = YES
 MTL_TREAT_WARNINGS_AS_ERRORS = YES
-SWIFT_TREAT_WARNINGS_AS_ERRORS = YES
 OTHER_SWIFT_FLAGS = $(inherited) -warnings-as-errors
 
 // User-specific overrides
diff --git a/Config/User.xcconfig.sample b/Config/User.xcconfig.sample
index 2e3d77d874..8311bb8549 100644
--- a/Config/User.xcconfig.sample
+++ b/Config/User.xcconfig.sample
@@ -3,5 +3,4 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 //
 
-SWIFT_TREAT_WARNINGS_AS_ERRORS = NO
 OTHER_SWIFT_FLAGS = $(inherited) -no-warnings-as-errors
diff --git a/Signal.xcodeproj/project.pbxproj b/Signal.xcodeproj/project.pbxproj
index 1db1e2fa23..83cbf4f849 100644
--- a/Signal.xcodeproj/project.pbxproj
+++ b/Signal.xcodeproj/project.pbxproj
@@ -20094,7 +20094,7 @@
 					"-DNS_BLOCK_ASSERTIONS=1",
 					"-DTESTABLE_BUILDS",
 				);
-				OTHER_SWIFT_FLAGS = "-DTESTABLE_BUILD";
+				OTHER_SWIFT_FLAGS = "$(inherited) -DTESTABLE_BUILD";
 				SDKROOT = iphoneos;
 				SIGNAL_BUNDLEID_PREFIX = org.whispersystems;
 				SIGNAL_MERCHANTID = org.signalfoundation;
@@ -20347,7 +20347,7 @@
 				IPHONEOS_DEPLOYMENT_TARGET = 15.0;
 				ONLY_ACTIVE_ARCH = YES;
 				OTHER_CFLAGS = "-DNS_BLOCK_ASSERTIONS=1";
-				OTHER_SWIFT_FLAGS = "-DTESTABLE_BUILD";
+				OTHER_SWIFT_FLAGS = "$(inherited) -DTESTABLE_BUILD";
 				SDKROOT = iphoneos;
 				SIGNAL_BUNDLEID_PREFIX = org.whispersystems;
 				SIGNAL_MERCHANTID = org.signalfoundation;
@@ -20605,7 +20605,7 @@
 				INFOPLIST_KEY_NSHumanReadableCopyright = "Copyright © 2024 Signal Messenger, LLC";
 				IPHONEOS_DEPLOYMENT_TARGET = 15.0;
 				ONLY_ACTIVE_ARCH = YES;
-				OTHER_SWIFT_FLAGS = "-DTESTABLE_BUILD -DUSE_DEBUG_UI";
+				OTHER_SWIFT_FLAGS = "$(inherited) -DTESTABLE_BUILD -DUSE_DEBUG_UI";
 				SDKROOT = iphoneos;
 				SIGNAL_BUNDLEID_PREFIX = org.whispersystems;
 				SIGNAL_MERCHANTID = org.signalfoundation;
@@ -20963,7 +20963,6 @@
 				SKIP_INSTALL = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_TREAT_WARNINGS_AS_ERRORS = NO;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VERSIONING_SYSTEM = "apple-generic";
 				VERSION_INFO_PREFIX = "";
@@ -21003,7 +21002,6 @@
 				SDKROOT = iphoneos;
 				SKIP_INSTALL = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
-				SWIFT_TREAT_WARNINGS_AS_ERRORS = NO;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VALIDATE_PRODUCT = YES;
 				VERSIONING_SYSTEM = "apple-generic";
@@ -21044,7 +21042,6 @@
 				SDKROOT = iphoneos;
 				SKIP_INSTALL = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
-				SWIFT_TREAT_WARNINGS_AS_ERRORS = NO;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VALIDATE_PRODUCT = YES;
 				VERSIONING_SYSTEM = "apple-generic";
@@ -21085,7 +21082,6 @@
 				SDKROOT = iphoneos;
 				SKIP_INSTALL = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
-				SWIFT_TREAT_WARNINGS_AS_ERRORS = NO;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VALIDATE_PRODUCT = YES;
 				VERSIONING_SYSTEM = "apple-generic";