diff --git a/libitm/ChangeLog b/libitm/ChangeLog
index 1be02b525b4..9a3e484fc8a 100644
--- a/libitm/ChangeLog
+++ b/libitm/ChangeLog
@@ -1,3 +1,8 @@
+2012-03-05  Torvald Riegel  <triegel@redhat.com>
+
+	* dispatch.h (CREATE_DISPATCH_METHODS_MEM): Don't execute
+	memtransfer/memset if size isn't larger than zero.
+
 2012-03-02  Torvald Riegel  <triegel@redhat.com>
 
 	* libitm.texi: Link to specification and add a usage example.
diff --git a/libitm/dispatch.h b/libitm/dispatch.h
index d059c493507..6a9e62ef6c0 100644
--- a/libitm/dispatch.h
+++ b/libitm/dispatch.h
@@ -102,11 +102,13 @@
 virtual void memtransfer(void *dst, const void* src, size_t size,    \
     bool may_overlap, ls_modifier dst_mod, ls_modifier src_mod)       \
 {                                                                     \
-  memtransfer_static(dst, src, size, may_overlap, dst_mod, src_mod); \
+  if (size > 0)                                                       \
+    memtransfer_static(dst, src, size, may_overlap, dst_mod, src_mod); \
 }                                                                     \
 virtual void memset(void *dst, int c, size_t size, ls_modifier mod)  \
 {                                                                     \
-  memset_static(dst, c, size, mod);                                  \
+  if (size > 0)                                                       \
+    memset_static(dst, c, size, mod);                                 \
 }
 
 #define CREATE_DISPATCH_METHODS_MEM_PV()  \