diff --git a/advent-of-code-2021.csproj b/advent-of-code-2021.csproj
index a675df4..cd2fde3 100644
--- a/advent-of-code-2021.csproj
+++ b/advent-of-code-2021.csproj
@@ -5,7 +5,7 @@
 		<TargetFramework>net6.0</TargetFramework>
 		<RootNamespace>aoc2021</RootNamespace>
 		<ImplicitUsings>enable</ImplicitUsings>
-		<Nullable>disable</Nullable>
+		<Nullable>enable</Nullable>
 		<ProduceReferenceAssembly>False</ProduceReferenceAssembly>
 		<EnforceCodeStyleInBuild>True</EnforceCodeStyleInBuild>
 	</PropertyGroup>
diff --git a/src/05.cs b/src/05.cs
index 96ed5a1..9419957 100644
--- a/src/05.cs
+++ b/src/05.cs
@@ -15,7 +15,7 @@ namespace aoc2021
 
             public bool Equals(Point other) => X == other.X && Y == other.Y;
 
-            public override bool Equals(object obj) => obj is Point point && Equals(point);
+            public override bool Equals(object? obj) => obj is Point point && Equals(point);
 
             public override int GetHashCode() => HashCode.Combine(X, Y);
         }
diff --git a/src/07.cs b/src/07.cs
index 2fee115..9a6c66a 100644
--- a/src/07.cs
+++ b/src/07.cs
@@ -16,8 +16,8 @@
         {
             var min = nums.Min();
             var max = nums.Max();
-            long minDist = 0;
-            int? minNum = null;
+            long minDist = long.MaxValue;
+            int minNum = 0;
             for (int i = min; i <= max; i++)
             {
                 long dist = 0;
@@ -26,14 +26,14 @@
                     dist += formula(Math.Abs(num - i));
                 }
 
-                if (minNum == null || dist < minDist)
+                if (dist < minDist)
                 {
                     minDist = dist;
                     minNum = i;
                 }
             }
 
-            return (minDist, minNum.Value);
+            return (minDist, minNum);
         }
 
         private static void Part1(IEnumerable<int> nums)