diff --git a/spl/std.spl b/spl/std.spl
index 3b516a5..152633f 100644
--- a/spl/std.spl
+++ b/spl/std.spl
@@ -648,7 +648,10 @@ func times { | with amount callable ;
 }
 
 func check-match { bool | with input output ;
-    output gettype "func" eq input null eq not and if {
+    input null eq if {
+        0 2 stop
+    }
+    output gettype "func" eq if {
         1 2 stop
     }
     input output eq if {
@@ -686,7 +689,10 @@ func match-unchecked { | with input output ;
 }
 
 func match { bool | with input output ;
-    output gettype "func" eq input null eq not and if {
+    input null eq if {
+        0 2 stop
+    }
+    output gettype "func" eq if {
         input output call
         1 2 stop
     }
diff --git a/src/lexer.rs b/src/lexer.rs
index dbb494a..9ac1f49 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -138,7 +138,7 @@ fn read_block_dyn(
                     run_as_base: false,
                 }))))
             }
-            x if x.len() >= 2 && &x[0..2] == "!{" => {
+            x if x.len() >= 2 && x.get(0..2) == Some("!{") => {
                 words.push(Word::Const(Value::Str(x[2..].to_owned())));
             }
             "<" => {