diff --git a/day5/p1.c b/day5/p1.c
index 0491fa1..ee8ebc4 100644
--- a/day5/p1.c
+++ b/day5/p1.c
@@ -70,7 +70,7 @@ int main(int argc, char **argv) {
 }
 
 inline uint64_t parse_number(const char *end) {
-    int64_t num = 0;
+    uint64_t num = 0;
 
     for (size_t m = 1;; m *= 10) {
         if (*end>>4 != 0x3)
diff --git a/day6/p1.c b/day6/p1.c
index 9d077b6..66608c4 100644
--- a/day6/p1.c
+++ b/day6/p1.c
@@ -97,7 +97,7 @@ int main(int argc, char **argv) {
 }
 
 inline uint64_t parse_number(const char *end) {
-    int64_t num = 0;
+    uint64_t num = 0;
 
     for (size_t m = 1;; m *= 10) {
         if (*end>>4 != 0x3)