diff --git a/AwsCryptographicMaterialProviders/runtimes/python/src/aws_cryptographic_material_providers/internaldafny/extern/StormTrackingCMC.py b/AwsCryptographicMaterialProviders/runtimes/python/src/aws_cryptographic_material_providers/internaldafny/extern/StormTrackingCMC.py
index 5164cebde..032187eb5 100644
--- a/AwsCryptographicMaterialProviders/runtimes/python/src/aws_cryptographic_material_providers/internaldafny/extern/StormTrackingCMC.py
+++ b/AwsCryptographicMaterialProviders/runtimes/python/src/aws_cryptographic_material_providers/internaldafny/extern/StormTrackingCMC.py
@@ -12,14 +12,18 @@ def __init__(self, wrapped):
 
     def PutCacheEntry(self, input):
         self.lock.Lock__()
-        val = self.wrapped.PutCacheEntry(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.PutCacheEntry(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def UpdateUsageMetadata(self, input):
         self.lock.Lock__()
-        val = self.wrapped.UpdateUsageMetadata(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.UpdateUsageMetadata(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     # NOT locked, as some sleeping might be involved
@@ -28,27 +32,35 @@ def GetCacheEntry(self, input):
     
     def DeleteCacheEntry(self, input):
         self.lock.Lock__()
-        val = self.wrapped.DeleteCacheEntry(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.DeleteCacheEntry(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def PutCacheEntry_k(self, input):
         self.lock.Lock__()
-        val = self.wrapped.PutCacheEntry(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.PutCacheEntry(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def UpdateUsageMetadata_k(self, input):
         self.lock.Lock__()
-        val = self.wrapped.UpdateUsageMetadata(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.UpdateUsageMetadata(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     # This is the synchronization for GetCacheEntry and GetCacheEntry_k
     def GetFromCacheInner(self, input):
         self.lock.Lock__()
-        val = self.wrapped.GetFromCache(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.GetFromCache(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     # NOT locked, because we sleep. Calls GetFromCache which IS synchronized.
@@ -73,8 +85,10 @@ def GetCacheEntry_k(self, input):
 
     def DeleteCacheEntry_k(self, input):
         self.lock.Lock__()
-        val = self.wrapped.DeleteCacheEntry(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.DeleteCacheEntry(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def __str__(self):
diff --git a/AwsCryptographicMaterialProviders/runtimes/python/src/aws_cryptographic_material_providers/internaldafny/extern/SynchronizedLocalCMC.py b/AwsCryptographicMaterialProviders/runtimes/python/src/aws_cryptographic_material_providers/internaldafny/extern/SynchronizedLocalCMC.py
index 122b54c84..2f08cd81c 100644
--- a/AwsCryptographicMaterialProviders/runtimes/python/src/aws_cryptographic_material_providers/internaldafny/extern/SynchronizedLocalCMC.py
+++ b/AwsCryptographicMaterialProviders/runtimes/python/src/aws_cryptographic_material_providers/internaldafny/extern/SynchronizedLocalCMC.py
@@ -12,56 +12,74 @@ def __init__(self, wrapped):
 
     def PutCacheEntry(self, input):
         self.lock.Lock__()
-        val = self.wrapped.PutCacheEntry(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.PutCacheEntry(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def UpdateUsageMetadata(self, input):
         self.lock.Lock__()
-        val = self.wrapped.UpdateUsageMetadata(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.UpdateUsageMetadata(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def GetCacheEntry(self, input):
         self.lock.Lock__()
-        val = self.wrapped.GetCacheEntry(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.GetCacheEntry(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def DeleteCacheEntry(self, input):
         self.lock.Lock__()
-        val = self.wrapped.DeleteCacheEntry(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.DeleteCacheEntry(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def PutCacheEntry_k(self, input):
         self.lock.Lock__()
-        val = self.wrapped.PutCacheEntry(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.PutCacheEntry(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def UpdateUsageMetadata_k(self, input):
         self.lock.Lock__()
-        val = self.wrapped.UpdateUsageMetadata(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.UpdateUsageMetadata(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def GetFromCacheInner(self, input):
         self.lock.Lock__()
-        val = self.wrapped.GetFromCache(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.GetFromCache(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def GetCacheEntry_k(self, input):
         self.lock.Lock__()
-        val = self.wrapped.GetCacheEntry(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.GetCacheEntry(input)
+        finally:
+            self.lock.Unlock()
         return val
 
     def DeleteCacheEntry_k(self, input):
         self.lock.Lock__()
-        val = self.wrapped.DeleteCacheEntry(input)
-        self.lock.Unlock()
+        try:
+            val = self.wrapped.DeleteCacheEntry(input)
+        finally:
+            self.lock.Unlock()
         return val
     
     def __str__(self):