diff --git a/engine/player/player.cpp b/engine/player/player.cpp
index c4cc379832c..9946f99a44c 100644
--- a/engine/player/player.cpp
+++ b/engine/player/player.cpp
@@ -12072,6 +12072,11 @@ std::unique_ptr<expr_t> player_t::create_expression( util::string_view expressio
     auto parts = util::string_split<util::string_view>( expression_str, "_" );
     double percent = -1.0;
 
+    if ( parts.size() < 3 )
+    {
+      throw sc_invalid_apl_argument( fmt::format( "Invalid 'time_to_' expression '{}'.", expression_str ) );
+    }
+
     if ( util::str_in_str_ci( parts[ 2 ], "die" ) )
     {
       percent = 0.0;
@@ -12828,6 +12833,11 @@ std::unique_ptr<expr_t> player_t::create_resource_expression( util::string_view
     {
       auto parts = util::string_split<util::string_view>( splits[ 1 ], "_" );
 
+      if ( parts.size() < 3 )
+      {
+        throw sc_invalid_apl_argument( fmt::format( "Invalid resource expression '{}'.", expression_str ) );
+      }
+
       // foo.time_to_max
       if ( util::str_in_str_ci( parts[ 2 ], "max" ) )
       {