diff --git a/transition_machine/src/ActionBank.cpp b/transition_machine/src/ActionBank.cpp
index d8f358f9be1331db600b55879dd30fa21bfabf7d..7dedf72aa5c146cb5333b8c1852d2cdcf8b2a511 100644
--- a/transition_machine/src/ActionBank.cpp
+++ b/transition_machine/src/ActionBank.cpp
@@ -578,7 +578,7 @@ std::vector<Action::BasicAction> ActionBank::str2sequence(const std::string & na
     auto undo = [](Config & c, Action::BasicAction &)
       {removeCharFromBuffer(c, "FORM", 0);};
     auto appliable = [](Config & c, Action::BasicAction &)
-      {return c.getTape("FORM").getHyp(0).size() <= 2000;};
+      {return c.getTape("FORM").getHyp(0).size() <= 2000 && c.rawInput[c.rawInputHeadIndex] != '\t';};
     Action::BasicAction basicAction =
       {Action::BasicAction::Type::Write, "", apply, undo, appliable};