diff --git a/.github/workflows/mac.yml b/.github/workflows/mac.yml
index d2e311a..bc7e864 100644
--- a/.github/workflows/mac.yml
+++ b/.github/workflows/mac.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: macos-13
     strategy:
       matrix:
-        xcode: ['14.1', '15.0']
+        xcode: ['15.0']
         build_type: [Debug, Release]
     env:
       DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
@@ -35,7 +35,6 @@ jobs:
     strategy:
       matrix:
         compiler:
-          - { cpp: g++-11, c: gcc-11}
           - { cpp: g++-12, c: gcc-12}
           - { cpp: clang++, c: clang}
         build_type: [Debug, Release]
diff --git a/src/day3.cpp b/src/day3.cpp
index bc2626b..48fb570 100644
--- a/src/day3.cpp
+++ b/src/day3.cpp
@@ -3,6 +3,7 @@
 #include <iostream>
 #include <string>
 #include <vector>
+#include <unordered_map>
 
 bool is_symbol(char c) { return !std::isdigit(c) && (c != '.'); }
 
diff --git a/src/day7.cpp b/src/day7.cpp
index 726f36b..1ee8826 100644
--- a/src/day7.cpp
+++ b/src/day7.cpp
@@ -6,6 +6,7 @@
 #include <numeric>
 #include <string>
 #include <vector>
+#include <unordered_map>
 
 enum Rank { None, FiveOfAKind, FourOfAKind, FullHouse, ThreeOfAKind, TwoPair, OnePair, HighCard };