diff --git a/nxscript.c b/nxscript.c
index 9fc7a277..ed3ad5c5 100644
--- a/nxscript.c
+++ b/nxscript.c
@@ -1008,6 +1008,8 @@ static void putSlab(SConnection * pCon, SicsInterp * pSics, pNXScript self,
       if (status == NX_OK) {
         written = 1;
       }
+      if (argc > 6)
+        free(histData);
     }
   }