diff --git a/lix/libstore/build-result.hh b/lix/libstore/build-result.hh
index ef7e64982..ba48dbba0 100644
--- a/lix/libstore/build-result.hh
+++ b/lix/libstore/build-result.hh
@@ -21,7 +21,7 @@ struct BuildResult
      * Therefore, don't remove status codes, and only add new status
      * codes at the end of the list.
      */
-    enum Status {
+    enum Status : uint8_t {
         Built = 0,
         Substituted,
         AlreadyValid,
diff --git a/lix/libstore/gc-store.hh b/lix/libstore/gc-store.hh
index 121c00ceb..7d04ae6a4 100644
--- a/lix/libstore/gc-store.hh
+++ b/lix/libstore/gc-store.hh
@@ -39,13 +39,13 @@ struct GCOptions
      *    Any that could not be deleted are returned via the
      *    `kept` field of GCResults.
      */
-    typedef enum {
+    enum GCAction : uint8_t {
         gcReturnLive,
         gcReturnDead,
         gcDeleteDead,
         gcDeleteSpecific,
         gcTryDeleteSpecific,
-    } GCAction;
+    };
 
     GCAction action{gcDeleteDead};
 
diff --git a/lix/libutil/error.hh b/lix/libutil/error.hh
index f1b9c29a2..2e1d8dfee 100644
--- a/lix/libutil/error.hh
+++ b/lix/libutil/error.hh
@@ -35,8 +35,7 @@
 
 namespace nix {
 
-
-typedef enum {
+enum Verbosity : uint8_t {
     lvlError = 0,
     lvlWarn,
     lvlNotice,
@@ -45,7 +44,7 @@ typedef enum {
     lvlChatty,
     lvlDebug,
     lvlVomit
-} Verbosity;
+};
 
 template<>
 struct json::is_integral_enum<Verbosity> : std::true_type {};