diff --git a/src/nmreval/models/bds.py b/src/nmreval/models/bds.py
index 9356de9..7e770e7 100644
--- a/src/nmreval/models/bds.py
+++ b/src/nmreval/models/bds.py
@@ -82,7 +82,7 @@ class HavriliakNegamiAlphaGammaBDS:
 class KWWBDS(_AbstractBDS):
     name = 'KWW'
     params = _AbstractBDS.params + [r'\beta']
-    bounds = _AbstractBDS.bounds + [(0, 1)]
+    bounds = _AbstractBDS.bounds + [(0.1, 1)]
     susceptibility = KWW.susceptibility
 
 
diff --git a/src/nmreval/models/fieldcycling.py b/src/nmreval/models/fieldcycling.py
index 4d5221e..a1082d9 100644
--- a/src/nmreval/models/fieldcycling.py
+++ b/src/nmreval/models/fieldcycling.py
@@ -66,7 +66,7 @@ class HavriliakNegamiFC(_AbstractFC):
 class KWWFC(_AbstractFC):
     name = 'KWW'
     params = _AbstractFC.params + [r'\beta']
-    bounds = _AbstractFC.bounds + [(0, 1)]
+    bounds = _AbstractFC.bounds + [(0.1, 1)]
     relax = Relaxation(distribution=KWW)