diff --git a/Makefile b/Makefile
index 8b3ee64..130caa3 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,10 @@
 
+check:
+	cargo test
+	cargo fmt --check
+	cargo clippy
+	cargo build --release
+
 run:
 	SECURE_SESSIONS=false RUST_LOG=debug cargo run -- --reload-templates
 
diff --git a/src/permissions.rs b/src/permissions.rs
index 5590545..1a0062b 100644
--- a/src/permissions.rs
+++ b/src/permissions.rs
@@ -42,6 +42,14 @@ pub mod q {
         };
 
         if row_count > 0 {
+            if row_count > 1 {
+                tracing::error!(
+                    row_count = row_count,
+                    user_id = user_id,
+                    project_id = project_id,
+                    "unexpected row count: more than one project membership for this user"
+                )
+            }
             Ok(Decision::Allowed)
         } else {
             Ok(Decision::Denied)