diff --git a/Source/Additions/NSThread+GNUstepBase.m b/Source/Additions/NSThread+GNUstepBase.m
index acd041329..690b544f0 100644
--- a/Source/Additions/NSThread+GNUstepBase.m
+++ b/Source/Additions/NSThread+GNUstepBase.m
@@ -26,7 +26,7 @@
 #import "common.h"
 #import "Foundation/NSThread.h"
 
-#if	defined(__APPLE__)
+#if	defined(NeXT_Foundation_LIBRARY)
 
 /* These functions are in NSThread.m in the base library.
  */
diff --git a/Source/Additions/Unicode.m b/Source/Additions/Unicode.m
index ebae453a7..baf86dd20 100644
--- a/Source/Additions/Unicode.m
+++ b/Source/Additions/Unicode.m
@@ -29,7 +29,9 @@
 */
 
 #import "common.h"
-#ifndef NeXT_Foundation_LIBRARY
+#if	defined(NeXT_Foundation_LIBRARY)
+#import <Foundation/Foundation.h>
+#else
 #import "Foundation/NSArray.h"
 #import "Foundation/NSBundle.h"
 #import "Foundation/NSDictionary.h"
@@ -37,8 +39,6 @@
 #import "Foundation/NSException.h"
 #import "Foundation/NSLock.h"
 #import "Foundation/NSPathUtilities.h"
-#else
-#import <Foundation/Foundation.h>
 #endif
 
 #import "GNUstepBase/GSLock.h"
diff --git a/Source/common.h b/Source/common.h
index 48f7f07ec..63f6d02d1 100644
--- a/Source/common.h
+++ b/Source/common.h
@@ -6,6 +6,14 @@
 
 #import	"config.h"
 
+/* If this is included in a file in the Additions subdirectory, and we are
+ * building for use with the NeXT/Apple Foundation, then we need to import
+ * the native headers in preference to any of our own.
+ */
+#if	defined(NeXT_Foundation_LIBRARY)
+#import	<Foundation/Foundation.h>
+#endif
+
 /* GNUstepBase/GSConfig.h includes <GNUstepBase/preface.h> so
  * we import local versions first.
  */