diff --git a/src/openai/_client.py b/src/openai/_client.py
index 499a62dfe5..c9459c101f 100644
--- a/src/openai/_client.py
+++ b/src/openai/_client.py
@@ -211,7 +211,7 @@ def __init__(
 
         if base_url is None:
             base_url = os.environ.get("OPENAI_BASE_URL")
-        if base_url is None:
+        if not base_url:
             base_url = f"https://api.openai.com/v1"
 
         custom_headers_env = os.environ.get("OPENAI_CUSTOM_HEADERS")
@@ -717,7 +717,7 @@ def __init__(
 
         if base_url is None:
             base_url = os.environ.get("OPENAI_BASE_URL")
-        if base_url is None:
+        if not base_url:
             base_url = f"https://api.openai.com/v1"
 
         custom_headers_env = os.environ.get("OPENAI_CUSTOM_HEADERS")