diff --git a/CHANGELOG.md b/CHANGELOG.md
index 064845e06..30355ea96 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,8 @@ The changelog for `IGListKit`. Also see the [releases](https://github.com/instag
 
 - Introduce `IGListSwiftKit`, with Swift refinements for `dequeueReusableCellOfClass` methods. [Koen Punt](https://github.com/koenpunt) [(#1388)](https://github.com/Instagram/IGListKit/pull/1388).
 
+- Added `APPLICATION_EXTENSION_API_ONLY` support for `IGListDiffKit` [Peter Meyers](https://github.com/pm-dev) [(#1422)](https://github.com/Instagram/IGListKit/pull/1422)
+
 4.0.0
 -----
 ### Breaking Changes
diff --git a/IGListKit.xcodeproj/project.pbxproj b/IGListKit.xcodeproj/project.pbxproj
index ef11ffb1e..1147d0f35 100644
--- a/IGListKit.xcodeproj/project.pbxproj
+++ b/IGListKit.xcodeproj/project.pbxproj
@@ -2093,6 +2093,7 @@
 		7A02D0232361520200B49FAE /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
 				CLANG_ENABLE_OBJC_WEAK = YES;
@@ -2120,6 +2121,7 @@
 		7A02D0242361520200B49FAE /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
 				CLANG_ENABLE_OBJC_WEAK = YES;
@@ -2146,6 +2148,7 @@
 		7A02D0312361525800B49FAE /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
 				CLANG_ENABLE_OBJC_WEAK = YES;
@@ -2175,6 +2178,7 @@
 		7A02D0322361525800B49FAE /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
 				CLANG_ENABLE_OBJC_WEAK = YES;
@@ -2203,6 +2207,7 @@
 		7A02D03E2361526600B49FAE /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
 				CLANG_ENABLE_OBJC_WEAK = YES;
@@ -2232,6 +2237,7 @@
 		7A02D03F2361526600B49FAE /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
 				CLANG_ENABLE_OBJC_WEAK = YES;