diff --git a/crates/agent_ui/src/acp/completion_provider.rs b/crates/agent_ui/src/acp/completion_provider.rs
index 3641e00bea3ccc8c10145fc33ae51d2afcc010d8..f0b0644f8e68d3908074dc9fc98a1eb4d91c16a4 100644
--- a/crates/agent_ui/src/acp/completion_provider.rs
+++ b/crates/agent_ui/src/acp/completion_provider.rs
@@ -1220,6 +1220,14 @@ mod tests {
         assert_eq!(SlashCommandCompletion::try_parse("Lorem/", 0), None);
 
         assert_eq!(SlashCommandCompletion::try_parse("/ ", 0), None);
+
+        // Slash commands should not consume @ symbols that could be mention triggers
+        assert_eq!(SlashCommandCompletion::try_parse("/init @", 0), None);
+
+        assert_eq!(SlashCommandCompletion::try_parse("/help @file", 0), None);
+
+        // @ with whitespace before it should also not be consumed
+        assert_eq!(SlashCommandCompletion::try_parse("/command  @", 0), None);
     }
 
     #[test]