diff --git a/powertrail.cpp b/powertrail.cpp
index a2ded84..c7f398b 100644
--- a/powertrail.cpp
+++ b/powertrail.cpp
@@ -44,7 +44,7 @@ PowertrailDB::~PowertrailDB() {
 	curl_easy_cleanup(curl);
 }
 
-void PowertrailDB::get_trail(int n) {
+void PowertrailDB::get_trail(uint n) {
 	CURLcode curl_res;
 	std::smatch res;
 
@@ -111,7 +111,7 @@ void PowertrailDB::read_from_json(std::string file) {
 	try {
 		json j;
 		datafile >> j;
-		data = j.get<std::unordered_map<int, Powertrail>>();
+		data = j.get<std::unordered_map<uint, Powertrail>>();
         }
         catch (...) {
                 Debug(1) << "Cache file: " << file << " corrupted.";
diff --git a/powertrail.h b/powertrail.h
index f88b7e8..14c1894 100644
--- a/powertrail.h
+++ b/powertrail.h
@@ -25,8 +25,8 @@ public:
 
 class PowertrailDB {
 public:
-	std::unordered_map<int, Powertrail> data;
-	void get_trail(int n);
+	std::unordered_map<uint, Powertrail> data;
+	void get_trail(uint n);
 
 	CURL* curl;
 	mutable std::string curl_output;