diff --git a/api.go b/api.go
index f273208..2817475 100644
--- a/api.go
+++ b/api.go
@@ -35,7 +35,7 @@ type ThinPackage struct {
 	DebugSymbols  dbpackage.DebugSymbols `json:"debug_symbols"`
 	ArchVersion   string                 `json:"arch_version"`
 	RepoVersion   string                 `json:"repo_version"`
-	BuildDate     string                 `json:"build_date"`
+	BuildDate     *string                `json:"build_date,omitempty"`
 	PeakMem       *string                `json:"peak_mem,omitempty"`
 }
 
@@ -171,7 +171,8 @@ func GetPackages(w http.ResponseWriter, r *http.Request) {
 		}
 
 		if !mPkg.BuildTimeStart.IsZero() {
-			nPkg.BuildDate = mPkg.BuildTimeStart.UTC().Format(time.RFC1123)
+			formattedBuildDate := mPkg.BuildTimeStart.UTC().Format(time.RFC1123)
+			nPkg.BuildDate = &formattedBuildDate
 		}
 
 		if mPkg.MaxRss != nil {