diff --git a/ast/token.go b/ast/token.go
index 721143a..645e203 100644
--- a/ast/token.go
+++ b/ast/token.go
@@ -152,6 +152,8 @@ func GetTagAsStr(tag Token_t) string {
         return "LIST"
     case STRING:
         return "STRING"
+    case BOOL:
+        return "BOOL"
     case NUMBER:
         return "NUMBER"
     case SYMBOL:
diff --git a/stdlib/control_flow.go b/stdlib/control_flow.go
index c14cb31..5889e33 100644
--- a/stdlib/control_flow.go
+++ b/stdlib/control_flow.go
@@ -63,7 +63,7 @@ func shs_while(in *ast.Token, vt ast.VarTable, ft ast.FuncTable) *ast.Token {
     var res *ast.Token
 
     eval := cond.Eval(ft, vt, false)
-    if cond == nil || cond.Tag != ast.BOOL {
+    if eval == nil || eval.Tag != ast.BOOL {
         log.Log(log.ERR,
             "first argument to while must be a bool statement",
             "while")