diff --git a/Tests/base/NSKVOSupport/legacy.m b/Tests/base/NSKVOSupport/legacy.m
new file mode 100644
index 000000000..5cb3625a4
--- /dev/null
+++ b/Tests/base/NSKVOSupport/legacy.m
@@ -0,0 +1,315 @@
+#import <GNUstepBase/GNUstep.h>
+
+#import <Foundation/NSObject.h>
+#import <Foundation/NSString.h>
+#import <Foundation/NSDictionary.h>
+#import <Foundation/NSSet.h>
+#import <Foundation/NSAutoreleasePool.h>
+#import <Foundation/NSKeyValueObserving.h>
+
+#import "Testing.h"
+
+@interface Observee : NSObject
+{
+    NSString *_firstName;
+    NSString *_middleName;
+    NSString *_lastName;
+}
+
+- (NSString *) firstName;
+- (void) setFirstName: (NSString *)name;
+
+- (NSString *) middleName;
+- (void) setMiddleName: (NSString *)name;
+
+- (NSString *) lastName;
+- (void) setLastName: (NSString *)name;
+
+- (NSString *) shortFullName;
+- (NSString *) fullName;
+
+@end
+
+@interface ObserveeMixed : Observee
+{
+    BOOL _trigger;
+}
+
+- (BOOL) trigger;
+- (void) setTrigger: (BOOL) trigger;
+
+@end
+
+@implementation Observee
+
+- (instancetype)init {
+  self = [super init];
+  _firstName = _middleName = _lastName = @"";
+  return self;
+}
+
+- (NSString *) firstName
+{
+    return _firstName;
+}
+- (void) setFirstName: (NSString *)name
+{
+    ASSIGN(_firstName, name);
+}
+- (NSString *) middleName
+{
+    return _middleName;
+}
+- (void) setMiddleName: (NSString *)name
+{
+    ASSIGN(_middleName, name);
+}
+- (NSString *) lastName
+{
+    return _lastName;
+}
+- (void) setLastName: (NSString *)name
+{
+    ASSIGN(_lastName, name);
+}
+
+- (NSString *) shortFullName {
+return [NSString stringWithFormat: @"%@ %@", _firstName, _lastName];
+}
+
+- (NSString *) fullName {
+return [NSString stringWithFormat: @"%@ %@ %@", _firstName, _middleName, _lastName];
+}
+
+@end
+
+@implementation ObserveeMixed
+
+- (BOOL) trigger
+{
+    return _trigger;
+}
+- (void) setTrigger: (BOOL) trigger
+{
+    _trigger = trigger;
+}
+
+// We expect this function to have priority over the legacy API
++ (NSSet *)keyPathsForValuesAffectingFullName
+{
+  return [NSSet setWithObject:@"trigger"];
+}
+
+@end
+
+@interface Observer : NSObject
+@end
+
+@implementation Observer
+{
+    @public
+    NSString *lastKeyPath;
+    id lastObject;
+    NSDictionary *lastChange;
+    int notificationCount;
+}
+
+- (void) resetValues
+{
+  lastKeyPath = nil;
+  lastObject = nil;
+  lastChange = nil;
+}
+
+- (void) resetCounter
+{
+    notificationCount = 0;
+}
+
+- (void)observeValueForKeyPath:(NSString *)keyPath
+                      ofObject:(id)object
+                        change:(NSDictionary *)change
+                       context:(void *)context
+{
+  notificationCount += 1;
+  lastKeyPath = keyPath;
+  lastObject = object;
+  lastChange = change;
+}
+
+@end
+
+void simpleDependency(void)
+{
+  Observer *o = [Observer new];
+  Observee *e = [Observee new];
+
+  NSArray *keys = [NSArray arrayWithObjects: @"firstName", @"lastName", nil];
+
+  [Observee setKeys: keys
+      triggerChangeNotificationsForDependentKey:@"fullName"];
+
+  NSSet *s = [Observee keyPathsForValuesAffectingValueForKey:@"fullName"];
+  NSSet *expectedSet = [NSSet setWithArray: keys];
+  PASS_EQUAL(s, expectedSet, "'keyPathsForValuesAffectingValueForKey:' returns the correct values affecting 'fullName'");
+
+  NSKeyValueObservingOptions opts =
+      NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew;
+
+  [e addObserver:o forKeyPath:@"fullName" options:opts context:NULL];
+
+  [e setFirstName:@"Hey"];
+
+  PASS_EQUAL(o->lastKeyPath, @"fullName", "last keypath is 'fullName'");
+  PASS_EQUAL(o->lastObject, e, "last change object is correct");
+  PASS(o->lastChange != nil, "last change is not nil");
+  PASS_EQUAL([o->lastChange valueForKey: NSKeyValueChangeNewKey], @"Hey  ", "new entry in change dict correct");
+  PASS_EQUAL([o->lastChange valueForKey: NSKeyValueChangeOldKey], @"  ", "old entry in change dict correct");
+  PASS(o->notificationCount == 1, "notification count is 1");
+
+  [e setMiddleName:@"Not"]; // no change notification
+
+  [e setLastName:@"You"];
+  PASS_EQUAL(o->lastKeyPath, @"fullName", "last keypath is 'fullName'");
+  PASS_EQUAL(o->lastObject, e, "last change object is correct");
+  PASS(o->lastChange != nil, "last change is not nil");
+  PASS_EQUAL([o->lastChange valueForKey: NSKeyValueChangeNewKey], @"Hey Not You", "new entry in change dict correct");
+  PASS_EQUAL([o->lastChange valueForKey: NSKeyValueChangeOldKey], @"Hey Not ", "old entry in change dict correct");
+  PASS(o->notificationCount == 2, "notification count is 2");
+
+  [e removeObserver:o forKeyPath:@"fullName"];
+
+  [o release];
+  [e release];
+}
+
+void registeringMultipleDependencies(void) {
+  Observer *o;
+  Observee *e;
+  NSArray *arr;
+  NSSet *s;
+  
+  o = [Observer new];
+  e = [Observee new];
+
+  arr = [NSArray arrayWithObject: @"firstName"];
+  [Observee setKeys:arr
+      triggerChangeNotificationsForDependentKey:@"fullName"];
+  s = [Observee keyPathsForValuesAffectingValueForKey:@"fullName"];
+  PASS_EQUAL(s, [NSSet setWithArray: arr], "expecting 'firstName' as affecting key for 'fullName'");
+    
+  arr = [NSArray arrayWithObject: @"middleName"];
+  [Observee setKeys: arr
+      triggerChangeNotificationsForDependentKey:@"fullName"];
+  s = [Observee keyPathsForValuesAffectingValueForKey:@"fullName"];
+  PASS_EQUAL(s, [NSSet setWithArray: arr], "expecting 'middleName' as affecting key for 'fullName'");
+
+  arr = [NSArray arrayWithObjects: @"firstName", @"lastName", nil];
+  [Observee setKeys:arr
+      triggerChangeNotificationsForDependentKey:@"shortFullName"];
+  s = [Observee keyPathsForValuesAffectingValueForKey:@"shortFullName"];
+  PASS_EQUAL(s, [NSSet setWithArray: arr], "expecting 'firstName' and 'lastName' as affecting key for 'fullName'");
+
+  NSKeyValueObservingOptions opts =
+      NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew;
+
+  [e addObserver:o forKeyPath:@"fullName" options:opts context:NULL];
+
+  [e setFirstName:@"Hey"];
+  PASS(o->notificationCount == 0, "no change notification received when modifying firstName");
+
+  [e setMiddleName:@"Not"];
+  PASS_EQUAL(o->lastKeyPath, @"fullName", "last keypath is 'fullName'");
+  PASS_EQUAL(o->lastObject, e, "last change object is correct");
+  PASS(o->lastChange != nil, "last change is not nil");
+  PASS_EQUAL([o->lastChange valueForKey: NSKeyValueChangeNewKey], @"Hey Not ", "new entry in change dict correct");
+  PASS_EQUAL([o->lastChange valueForKey: NSKeyValueChangeOldKey], @"Hey  ", "old entry in change dict correct");
+  PASS(o->notificationCount == 1, "change notification received when modifying middleName");
+
+  [e setLastName:@"You"];
+  PASS(o->notificationCount == 1, "no change notification received when modifying lastName");
+
+  [e removeObserver:o forKeyPath:@"fullName"];
+  [o resetCounter];
+  [o resetValues];
+
+  [e addObserver:o forKeyPath:@"shortFullName" options:opts context:NULL];
+
+  [e setFirstName:@"Hello"];
+  PASS_EQUAL(o->lastKeyPath, @"shortFullName", "last keypath is 'shortFullName'");
+  PASS_EQUAL(o->lastObject, e, "last change object is correct");
+  PASS(o->lastChange != nil, "last change is not nil");
+  PASS_EQUAL([o->lastChange valueForKey: NSKeyValueChangeNewKey], @"Hello You", "new entry in change dict correct");
+  PASS_EQUAL([o->lastChange valueForKey: NSKeyValueChangeOldKey], @"Hey You", "old entry in change dict correct");
+  PASS(o->notificationCount == 1, "change notification received when modifying firstName");
+
+  [e setMiddleName:@"Not"];
+  PASS(o->notificationCount == 1, "no change notification received when modifying middleName");
+
+  [o resetValues];
+
+  [e setLastName:@"World"];
+  PASS_EQUAL(o->lastKeyPath, @"shortFullName", "last keypath is 'shortFullName'");
+  PASS_EQUAL(o->lastObject, e, "last change object is correct");
+  PASS(o->lastChange != nil, "last change is not nil");
+  PASS_EQUAL([o->lastChange valueForKey: NSKeyValueChangeNewKey], @"Hello World", "new entry in change dict correct");
+  PASS_EQUAL([o->lastChange valueForKey: NSKeyValueChangeOldKey], @"Hello You", "old entry in change dict correct");
+  PASS(o->notificationCount == 2, "change notification received when modifying lastName");
+
+  [e removeObserver:o forKeyPath:@"shortFullName"];
+
+  [o release];
+  [e release];
+}
+
+void mixedLegacy(void)
+{
+  Observer *o = [Observer new];
+  ObserveeMixed *e = [ObserveeMixed new];
+
+  NSArray *keys = [NSArray arrayWithObjects: @"firstName", @"lastName", nil];
+
+  [ObserveeMixed setKeys:keys
+      triggerChangeNotificationsForDependentKey:@"fullName"];
+
+  NSSet *s = [ObserveeMixed keyPathsForValuesAffectingValueForKey:@"fullName"];
+  NSSet *expected = [NSSet setWithObject:@"trigger"];
+  PASS_EQUAL(s, expected, "newer API has precedence over deprecated API");
+
+
+  NSKeyValueObservingOptions opts =
+      NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew;
+
+  [e addObserver:o forKeyPath:@"fullName" options:opts context:NULL];
+
+  // No trigger
+
+  [e setFirstName:@"Hey"];
+  [e setMiddleName:@"Not"];
+  [e setLastName:@"You"];
+  PASS(o->notificationCount == 0, "no change notification from either firstName, middleName, or lastName");
+
+  // Trigger
+
+  [e setTrigger:YES];
+  PASS(o->notificationCount == 1, "change notification from trigger");
+
+  [e removeObserver:o forKeyPath:@"fullName"];
+  [o release];
+  [e release];
+}
+
+
+int
+main(int argc, char *argv[])
+{
+    START_SET("KVO Legacy Tests")
+
+    simpleDependency();
+    registeringMultipleDependencies();
+    mixedLegacy();
+
+    END_SET("KVO Legacy Tests")
+
+    return 0;
+}