diff --git a/api/wireguard_manager.py b/api/wireguard_manager.py
index 0807428..524c5f8 100644
--- a/api/wireguard_manager.py
+++ b/api/wireguard_manager.py
@@ -294,6 +294,8 @@ class WireGuardManager(BaseServiceManager):
         return self.generate_config()
 
     def _write_config(self, content: str):
+        if content and not content.endswith('\n'):
+            content += '\n'
         with open(self._config_file(), 'w') as f:
             f.write(content)
         self._syncconf()
@@ -805,12 +807,20 @@ class WireGuardManager(BaseServiceManager):
         """Remove the [Peer] block matching public_key from wg0.conf."""
         try:
             content = self._read_config()
-            # Split on blank lines between blocks
-            raw_blocks = ('\n' + content).split('\n\n')
+            # Normalise to ensure blank-line block separators before splitting.
+            # Without this, a file written without trailing newline will merge
+            # [Interface] and the first [Peer] into one block, and the filter
+            # below would then delete [Interface] together with the peer.
+            normalised = content.replace('\n[Peer]', '\n\n[Peer]')
+            raw_blocks = ('\n' + normalised).split('\n\n')
             new_blocks = [
                 b for b in raw_blocks
                 if not (f'PublicKey = {public_key}' in b and '[Peer]' in b)
             ]
+            # Never write an empty file — that would destroy the [Interface] block.
+            if not any('[Interface]' in b for b in new_blocks):
+                logger.error('remove_peer: [Interface] block would be lost — aborting write')
+                return False
             self._write_config('\n\n'.join(new_blocks).lstrip('\n'))
             return True
         except Exception as e: