diff --git a/src/routes/mod.rs b/src/routes/mod.rs
index 770adcc..88862d3 100644
--- a/src/routes/mod.rs
+++ b/src/routes/mod.rs
@@ -13,6 +13,7 @@ use pacco::pkg::arch::Architecture;
 use pacco::pkg::{Package, Repository};
 
 use pacco::config::Config;
+use serde_json::json;
 
 pub mod push;
 pub mod ui;
@@ -174,3 +175,15 @@ pub fn is_repo_db(pkg_name: &str) -> bool {
         || pkg_name.ends_with("db.tar.gz.sig")
         || pkg_name.ends_with("db.sig")
 }
+
+pub fn no_such_repo_error() -> serde_json::Value {
+    json!({
+        "err": "No such repository"
+    })
+}
+
+pub fn no_such_pkg_error() -> serde_json::Value {
+    json!({
+        "err": "No such package"
+    })
+}
diff --git a/src/routes/ui/pkg.rs b/src/routes/ui/pkg.rs
index 8c95674..1e4569c 100644
--- a/src/routes/ui/pkg.rs
+++ b/src/routes/ui/pkg.rs
@@ -11,23 +11,38 @@ use rocket::{State, get};
 use pacco::pkg::{Package, Repository, arch::Architecture, find_package_by_name};
 use serde_json::json;
 
+use crate::routes::{no_such_pkg_error, no_such_repo_error};
+
 use super::take_out;
 
 /// Package API Endpoint
 #[get("/json/pkg/<repo>/<pkg_name>?<ver>&<arch>")]
-pub async fn pkg_json(repo: &str, pkg_name: &str, ver: Option<&str>, arch: Option<&str>) -> serde_json::Value {
-    let repository = Repository::new(repo).unwrap();
-    let mut pkg = repository.get_pkg_by_name(pkg_name).unwrap();
+pub async fn pkg_json(
+    repo: &str,
+    pkg_name: &str,
+    ver: Option<&str>,
+    arch: Option<&str>,
+) -> Result<serde_json::Value, serde_json::Value> {
+    let repository = Repository::new(repo).ok_or_else(no_such_repo_error)?;
+    let mut pkg = repository
+        .get_pkg_by_name(pkg_name)
+        .ok_or_else(no_such_pkg_error)?;
 
     if let Some(ver) = ver {
         let (version, rel) = Package::version(ver);
         pkg = pkg.get_version(&version);
         pkg.rel = rel;
+        if !pkg.exists() {
+            return Err(no_such_pkg_error());
+        }
     }
 
     if let Some(arch) = arch {
         let arch = Architecture::parse(arch).unwrap();
         pkg = pkg.switch_arch(arch);
+        if !pkg.exists() {
+            return Err(no_such_pkg_error());
+        }
     }
 
     let versions = pkg.versions();
@@ -35,14 +50,14 @@ pub async fn pkg_json(repo: &str, pkg_name: &str, ver: Option<&str>, arch: Optio
     let arch = pkg.arch();
     let pkginfo = pkg.pkginfo();
 
-    json!({
+    Ok(json!({
         "repo": repo,
         "pkg": pkg_name,
         "versions": versions,
         "version": version,
         "arch": arch.iter().map(|x| x.to_string()).collect::<Vec<_>>(),
         "info": pkginfo
-    })
+    }))
 }
 
 /// Package overview UI
diff --git a/src/routes/ui/repo.rs b/src/routes/ui/repo.rs
index d3b0925..0a7cf15 100644
--- a/src/routes/ui/repo.rs
+++ b/src/routes/ui/repo.rs
@@ -8,6 +8,7 @@ use rocket::{State, get};
 use pacco::pkg::{Repository, arch::Architecture};
 use serde_json::json;
 
+use crate::routes::no_such_repo_error;
 use crate::routes::ui::arch_card;
 use pacco::config::Config;
 
@@ -18,18 +19,18 @@ pub async fn repo_arch_json(
     ctx: RequestContext,
     arch: &str,
     config: &State<Config>,
-) -> serde_json::Value {
+) -> Result<serde_json::Value, serde_json::Value> {
     let arch = Architecture::parse(arch).unwrap_or(Architecture::any);
     let repo_name = repo;
 
-    let repo = Repository::new(repo_name).unwrap();
+    let repo = Repository::new(repo_name).ok_or_else(no_such_repo_error)?;
     let packages = repo.list_pkg_arch(arch.clone());
 
-    json!({
+    Ok(json!({
         "repo": repo_name,
         "arch": arch.to_string(),
         "packages": packages
-    })
+    }))
 }
 
 /// Repository Overview UI