diff --git a/src/celpy/celtypes.py b/src/celpy/celtypes.py
index 3e47271..3b76a26 100644
--- a/src/celpy/celtypes.py
+++ b/src/celpy/celtypes.py
@@ -398,6 +398,12 @@ def __new__(cls: Type["BoolType"], source: Any) -> "BoolType":
             return source
         elif isinstance(source, MessageType):
             return super().__new__(cls, cast(int, source.get(StringType("value"))))
+        elif isinstance(source, (str, StringType)):
+            if source in ("False", "f", "FALSE", "false"):
+                return super().__new__(cls, 0)
+            elif source in ("True", "t", "TRUE", "true"):
+                return super().__new__(cls, 1)
+            return super().__new__(cls, source)
         else:
             return super().__new__(cls, source)
 
diff --git a/tools/wip.toml b/tools/wip.toml
index b2b0709..ec41079 100644
--- a/tools/wip.toml
+++ b/tools/wip.toml
@@ -225,16 +225,6 @@ not_ne_int_uint = "@wip"
 not_ne_uint_double = "@wip"
 not_ne_uint_double_nan = "@wip"
 
-[conversions.bool]
-string_f = "@wip"
-string_false_lowercase = "@wip"
-string_false_pascalcase = "@wip"
-string_false_uppercase = "@wip"
-string_t = "@wip"
-string_true_lowercase = "@wip"
-string_true_pascalcase = "@wip"
-string_true_uppercase = "@wip"
-
 [conversions.identity]
 timestamp = "@wip"