diff --git a/Source/WTF/ChangeLog b/Source/WTF/ChangeLog
index 3d191fa..e0e07e6 100644
--- a/Source/WTF/ChangeLog
+++ b/Source/WTF/ChangeLog
@@ -1,3 +1,12 @@
+2020-01-16  Tim Horton  <timothy_horton@apple.com>
+
+        Fix the build after r254701
+        <rdar://problem/58667355>
+
+        * wtf/Platform.h:
+        * wtf/PlatformEnable.h:
+        AdditionalFeatureDefines has to come first.
+
 2020-01-16  Sam Weinig  <weinig@apple.com>
 
         Platform.h is out of control Part 7: Split calling convention macro definitions out of Platform.h and into a new PlatformCallingConventions.h
diff --git a/Source/WTF/wtf/Platform.h b/Source/WTF/wtf/Platform.h
index cefc287..2457a6c 100644
--- a/Source/WTF/wtf/Platform.h
+++ b/Source/WTF/wtf/Platform.h
@@ -73,10 +73,6 @@
 #include <WebKitAdditions/AdditionalPlatform.h>
 #endif
 
-#if USE(APPLE_INTERNAL_SDK) && __has_include(<WebKitAdditions/AdditionalFeatureDefines.h>)
-#include <WebKitAdditions/AdditionalFeatureDefines.h>
-#endif
-
 
 #undef WTF_PLATFORM_GUARD_AGAINST_INDIRECT_INCLUSION
 
diff --git a/Source/WTF/wtf/PlatformEnable.h b/Source/WTF/wtf/PlatformEnable.h
index 4f307e9..ced9412 100644
--- a/Source/WTF/wtf/PlatformEnable.h
+++ b/Source/WTF/wtf/PlatformEnable.h
@@ -69,6 +69,12 @@
 #endif
 #endif
 
+/* ==== Platform additions: additions to PlatformEnable.h from outside the main repository ==== */
+
+#if USE(APPLE_INTERNAL_SDK) && __has_include(<WebKitAdditions/AdditionalFeatureDefines.h>)
+#include <WebKitAdditions/AdditionalFeatureDefines.h>
+#endif
+
 /* FIXME: Move out the PLATFORM specific rules into platform specific files. */
 
 /* --------- Apple iOS (but not macOS) port --------- */