diff --git a/src/WINNT/afsd/afsd_init.c b/src/WINNT/afsd/afsd_init.c
index e8a42f0ef8..fbb012d477 100644
--- a/src/WINNT/afsd/afsd_init.c
+++ b/src/WINNT/afsd/afsd_init.c
@@ -310,7 +310,7 @@ configureBackConnectionHostNames(void)
             *pName = '\0';  /* add a second nul terminator */
 
             dwType = REG_MULTI_SZ;
-            dwSize += pName - pHostNames + 1;
+            dwSize = pName - pHostNames + 1;
             RegSetValueEx( hkMSV10, "BackConnectionHostNames", 0, dwType, pHostNames, dwSize);
 
             if ( RegOpenKeyEx( HKEY_LOCAL_MACHINE,