diff --git a/rsconnect/environment.py b/rsconnect/environment.py
index a2851b3b..5df5d5ca 100644
--- a/rsconnect/environment.py
+++ b/rsconnect/environment.py
@@ -218,7 +218,7 @@ def pip_freeze():
     """
     try:
         proc = subprocess.Popen(
-            [sys.executable, "-m", "pip", "list", "--format=freeze"],
+            [sys.executable, "-m", "pip", "freeze"],
             stdout=subprocess.PIPE,
             stderr=subprocess.PIPE,
             universal_newlines=True,