diff --git a/build/CodeGen/Stage2/KeysCodeGen.cs b/build/CodeGen/Stage2/KeysCodeGen.cs
index 4077ba5a..c9eee6e7 100644
--- a/build/CodeGen/Stage2/KeysCodeGen.cs
+++ b/build/CodeGen/Stage2/KeysCodeGen.cs
@@ -91,7 +91,7 @@ namespace LibHacBuild.CodeGen.Stage2
             var keySet = new KeySet();
 
             // Populate the key set with all the keys in IncludedKeys.txt
-            using (Stream keyFile = Common.GetResource(InputMainKeyFileName))
+            using (Stream keyFile = GetResource(InputMainKeyFileName))
             {
                 List<KeyInfo> list = KeySet.CreateKeyInfoList();
                 ExternalKeyReader.ReadMainKeys(keySet, keyFile, list);
diff --git a/src/LibHac/Common/Keys/ExternalKeyReader.cs b/src/LibHac/Common/Keys/ExternalKeyReader.cs
index 34c14cc6..cbe476ff 100644
--- a/src/LibHac/Common/Keys/ExternalKeyReader.cs
+++ b/src/LibHac/Common/Keys/ExternalKeyReader.cs
@@ -67,14 +67,6 @@ namespace LibHac.Common.Keys
             }
 
             keySet.DeriveKeys(logger);
-
-            // Dev keys can be read from prod key files, so derive any missing keys if necessary.
-            if (keySet.CurrentMode == KeySet.Mode.Prod)
-            {
-                keySet.SetMode(KeySet.Mode.Dev);
-                keySet.DeriveKeys(logger);
-                keySet.SetMode(KeySet.Mode.Prod);
-            }
         }
 
         /// <summary>
@@ -122,14 +114,6 @@ namespace LibHac.Common.Keys
             }
 
             keySet.DeriveKeys(logger);
-
-            // Dev keys can read from prod key files, so derive any missing keys if necessary.
-            if (keySet.CurrentMode == KeySet.Mode.Prod)
-            {
-                keySet.SetMode(KeySet.Mode.Dev);
-                keySet.DeriveKeys(logger);
-                keySet.SetMode(KeySet.Mode.Prod);
-            }
         }
 
         /// <summary>
diff --git a/src/LibHac/Common/Keys/KeySet.cs b/src/LibHac/Common/Keys/KeySet.cs
index 490809fb..79b7e32c 100644
--- a/src/LibHac/Common/Keys/KeySet.cs
+++ b/src/LibHac/Common/Keys/KeySet.cs
@@ -207,7 +207,19 @@ namespace LibHac.Common.Keys
             return DefaultKeySet.CreateKeyList();
         }
 
-        public void DeriveKeys(IProgressReport logger = null) => KeyDerivation.DeriveAllKeys(this, logger);
+        public void DeriveKeys(IProgressReport logger = null)
+        {
+            Mode originalMode = CurrentMode;
+
+            SetMode(Mode.Prod);
+            KeyDerivation.DeriveAllKeys(this, logger);
+
+            SetMode(Mode.Dev);
+            KeyDerivation.DeriveAllKeys(this, logger);
+
+            SetMode(originalMode);
+        }
+
         public void DeriveSdCardKeys() => KeyDerivation.DeriveSdCardKeys(this);
 
         private static RSAParameters CreateRsaParameters(in RsaKey key)