diff --git a/hyp3_gamma/__main__.py b/hyp3_gamma/__main__.py
index b7bc5e37..0f1710fc 100644
--- a/hyp3_gamma/__main__.py
+++ b/hyp3_gamma/__main__.py
@@ -114,9 +114,9 @@ def rtc():
 
 def phase_filter_valid_range(x: str) -> float:
     x = float(x)
-    if 0.0 <= x <= 1.0:
+    if 0.0 < x <= 1.0:
         return x
-    raise ValueError(f'{x} not in range [0.0, 1.0]')
+    raise ValueError(f'{x} not in range (0.0, 1.0]')
 
 
 def insar():