diff --git a/ChangeLog b/ChangeLog
index b17082ab6..8e95e240e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-11-24  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/NSObject.m: ([methodSignatureForSelector:]) Check that the
+	types of the selector (if known) and the types of the actual method
+	match.  Raise an NSInternalInconsistencyException if they don't.
+
 2008-11-23  Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Source/Additions/unicode/gsm0338.h: Add more mappings from unicode
diff --git a/Source/NSObject.m b/Source/NSObject.m
index e7b112cb2..4f63ef7c6 100644
--- a/Source/NSObject.m
+++ b/Source/NSObject.m
@@ -1599,6 +1599,7 @@ GSDescriptionForClassMethod(pcl self, SEL aSel)
  */
 - (NSMethodSignature*) methodSignatureForSelector: (SEL)aSelector
 {
+  const char		*selTypes;
   const char		*types;
   struct objc_method	*mth;
   Class			c;
@@ -1607,6 +1608,7 @@ GSDescriptionForClassMethod(pcl self, SEL aSel)
     [NSException raise: NSInvalidArgumentException
 		format: @"%@ null selector given", NSStringFromSelector(_cmd)];
 
+  selTypes = sel_get_type(aSelector);
   c = (GSObjCIsInstance(self) ? GSObjCClass(self) : (Class)self);
   mth = GSGetMethod(c, aSelector, GSObjCIsInstance(self), YES);
 
@@ -1663,6 +1665,13 @@ GSDescriptionForClassMethod(pcl self, SEL aSel)
     {
       return nil;
     }
+  else if (selTypes != 0 && GSSelectorTypesMatch(selTypes, types) == NO)
+    {
+      [NSException raise: NSInternalInconsistencyException
+	format: @"[%@%c%@] selector types (%s) don't match method types (%s)",
+	NSStringFromClass(c), (GSObjCIsInstance(self) ? '-' : '+'),
+	NSStringFromSelector(aSelector), selTypes, types];
+    }
   return [NSMethodSignature signatureWithObjCTypes: types];
 }