diff --git a/generator.cpp b/generator.cpp
index ac9a8f7..8e6862f 100644
--- a/generator.cpp
+++ b/generator.cpp
@@ -122,7 +122,7 @@ auto Generator::do_crypto() -> std::string {
 auto Generator::generate_blocks(unsigned int k_blocks) -> std::string {
 	assert ((G.ctr!=0) && "Counter is not 0, generator has been seeded");
 	std::string r{""};
-	for (int i = 0; i < k_blocks; ++i) {
+	for (uint i = 0; i < k_blocks; ++i) {
 		r += do_crypto();
 		++G.ctr;
 	}
diff --git a/pool.h b/pool.h
index df2e01a..f625297 100644
--- a/pool.h
+++ b/pool.h
@@ -32,7 +32,7 @@ public:
 		const size_t event_size{event.size()};
 
 		try {
-			if (source < 0 || source > 255) {
+			if (source > 255) {
 				throw std::invalid_argument("source number outside of interval <0,255>\n");
 			}
 			if (event_size < 1 || event_size > 32) {