diff --git a/ChangeLog b/ChangeLog
index d339b7c71..38aa12fa8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2010-06-15  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/NSInvocation: For portability, use NSPageSize() to find
+	size for page alignment.
+
 2010-06-15 Riccardo Mottola
 
 	* Source/NSInvocation:
diff --git a/Source/NSInvocation.m b/Source/NSInvocation.m
index 17d63eb52..316db63fd 100644
--- a/Source/NSInvocation.m
+++ b/Source/NSInvocation.m
@@ -31,6 +31,7 @@
 #import "Foundation/NSException.h"
 #import "Foundation/NSCoder.h"
 #import "Foundation/NSInvocation.h"
+#import "Foundation/NSZone.h"
 #import "GSInvocation.h"
 #import "GSPrivate.h"
 #import "GNUstepBase/NSObject+GNUstepBase.h"
@@ -81,7 +82,7 @@
       VirtualFree(buffer, 0, MEM_RELEASE);
 #else
 #if     defined(HAVE_MPROTECT)
-      if (mprotect(buffer,sysconf(_SC_PAGESIZE), PROT_READ|PROT_WRITE) == -1)
+      if (mprotect(buffer, NSPageSize(), PROT_READ|PROT_WRITE) == -1)
 	{
 	  NSLog(@"Failed to protect memory as writable: %@", [NSError _last]);
 	}
@@ -114,8 +115,8 @@
   buffer = VirtualAlloc(NULL, _size, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE);
 #else
 //  buffer = malloc(_size);
-  NSAssert(_size < sysconf(_SC_PAGESIZE), @"Tried to allocate more than one page.");
-  buffer = valloc(sysconf(_SC_PAGESIZE));
+  NSAssert(_size < NSPageSize(), @"Tried to allocate more than one page.");
+  buffer = valloc(NSPageSize());
 #endif  /* HAVE_MMAP */
 
   if (buffer == (void*)0)
@@ -144,7 +145,7 @@
       NSLog(@"Failed to protect memory as executable: %@", [NSError _last]);
     }
 #elif     defined(HAVE_MPROTECT)
-  if (mprotect(buffer,sysconf(_SC_PAGESIZE), PROT_READ|PROT_EXEC) == -1)
+  if (mprotect(buffer, NSPageSize(), PROT_READ|PROT_EXEC) == -1)
     {
       NSLog(@"Failed to protect memory as executable: %@", [NSError _last]);
     }