diff --git a/Docs/src/history.but b/Docs/src/history.but
index fb3e6b5e..e9c27617 100644
--- a/Docs/src/history.but
+++ b/Docs/src/history.but
@@ -24,6 +24,8 @@ Released on ?, 2014
 
 \b Fixed POSIX !searchparse bug (\W{http://sf.net/p/nsis/patches/251}{patch #251})
 
+\b Fixed !macroundef
+
 \S2{} Translations
 
 \b Added Armenian (Hrant Ohanyan)
@@ -98,8 +100,6 @@ It's the holiday gift you've been waiting for!
 
 \b Unicode stubs create WCHAR richedit controls (\W{http://sf.net/p/nsis/bugs/1080/}{bug #1080})
 
-\b Fixed !macroundef
-
 \b Fixed MakeNSISW default pushbutton and tab order
 
 \b Fixed incorrect page count in compiler statistics
diff --git a/Source/script.cpp b/Source/script.cpp
index 4d857bb3..ca5464cf 100644
--- a/Source/script.cpp
+++ b/Source/script.cpp
@@ -1212,7 +1212,7 @@ int CEXEBuild::doCommand(int which_token, LineParser &line)
         }
         TCHAR *mbufb=(TCHAR*)m_macros.get();
         const unsigned int mcb=BUGBUG64TRUNCATE(unsigned int, (mend-mbeg)*sizeof(TCHAR)), mbufcb=m_macros.getlen();
-        memmove(mbeg,mend+sizeof(TCHAR),mbufcb-(mcb+(mbeg-mbufb)));
+        memmove(mbeg,mend+1,mbufcb-(mcb+(mbeg-mbufb)));
         m_macros.resize((int)(mbufcb-(mcb+sizeof(TCHAR))));
         SCRIPT_MSG(_T("!macroundef: %") NPRIs _T("\n"),mname);
       }