diff --git a/src/day7.cpp b/src/day7.cpp
index 3f8a6fe..e87b055 100644
--- a/src/day7.cpp
+++ b/src/day7.cpp
@@ -35,8 +35,8 @@ char at_loc(const Grid &grid, size_t row, size_t col) {
 }
 
 Location find_start(const Grid &grid) {
-  for (int64_t row{0}; row < grid.size(); ++row) {
-    for (int64_t col{0}; col < grid[row].length(); ++col) {
+  for (size_t row{0}; row < grid.size(); ++row) {
+    for (size_t col{0}; col < grid[row].length(); ++col) {
       if (grid[row][col] == 'S') {
         return {row, col};
       }
@@ -68,7 +68,7 @@ uint64_t part_1(const Grid &grid) {
 }
 
 void insert_or_increment(std::map<size_t, uint64_t> &cols, size_t col,
-                         int64_t value) {
+                         uint64_t value) {
   auto iter = cols.find(col);
   if (iter == cols.end()) {
     cols.insert({col, value});