diff --git a/tap_hubspot_beta/client_base.py b/tap_hubspot_beta/client_base.py
index 1ea98f0..4957fb8 100644
--- a/tap_hubspot_beta/client_base.py
+++ b/tap_hubspot_beta/client_base.py
@@ -349,7 +349,7 @@ def process_row_types(self,row) -> Dict[str, Any]:
             if field_type == "boolean":
                 if value is None:
                     row[field] = False
-                elif not isinstance(value, bool):
+                elif isinstance(value, str):
                     # Attempt to cast to boolean
                     if value.lower() == "true":
                         row[field] = True