diff --git a/virtualsmartcard/src/pcsclite-vpcd/winscard.c b/virtualsmartcard/src/pcsclite-vpcd/winscard.c
index 8776d44..bd91697 100644
--- a/virtualsmartcard/src/pcsclite-vpcd/winscard.c
+++ b/virtualsmartcard/src/pcsclite-vpcd/winscard.c
@@ -541,7 +541,7 @@ PCSC_API LONG SCardListReaders(SCARDCONTEXT hContext, LPCSTR mszGroups, LPSTR ms
 
 
     SET_R_TEST( autoallocate(mszReaders, pcchReaders,
-                (MAX_READERNAME+1)*PCSCLITE_MAX_READERS_CONTEXTS,
+                (MAX_READERNAME+1)*PCSCLITE_MAX_READERS_CONTEXTS+1,
                 (void **) &readers));
 
 
@@ -560,6 +560,12 @@ PCSC_API LONG SCardListReaders(SCARDCONTEXT hContext, LPCSTR mszGroups, LPSTR ms
         readerslen++;
     }
 
+    /* write a null character as final delimiter */
+    if (readers) {
+        readers[readerslen] = '\0';
+    }
+    readerslen++;
+
     *pcchReaders = readerslen;
 
     if (!readerslen) {