diff --git a/ObjectiveGitFramework.xcodeproj/project.pbxproj b/ObjectiveGitFramework.xcodeproj/project.pbxproj
index bdfc1d91..1a3e1ac9 100644
--- a/ObjectiveGitFramework.xcodeproj/project.pbxproj
+++ b/ObjectiveGitFramework.xcodeproj/project.pbxproj
@@ -1390,9 +1390,12 @@
 			files = (
 			);
 			inputPaths = (
+				"$(SRCROOT)/script/update_libgit2",
+				"$(SRCROOT)/External/libgit2/CMakeLists.txt",
 			);
 			name = libgit2;
 			outputPaths = (
+				"$(SRCROOT)/External/libgit2.a",
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
@@ -1743,6 +1746,7 @@
 				CLANG_WARN_STRICT_PROTOTYPES = YES;
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				ENABLE_TESTABILITY = YES;
+				EXCLUDED_ARCHS = x86_64;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = NO;
 				GCC_WARN_ABOUT_MISSING_FIELD_INITIALIZERS = NO;
@@ -1783,6 +1787,7 @@
 				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
 				CLANG_WARN_STRICT_PROTOTYPES = YES;
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
+				EXCLUDED_ARCHS = x86_64;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = NO;
 				GCC_WARN_ABOUT_MISSING_FIELD_INITIALIZERS = NO;
@@ -1918,6 +1923,7 @@
 				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
 				CLANG_WARN_STRICT_PROTOTYPES = YES;
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
+				EXCLUDED_ARCHS = x86_64;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = NO;
 				GCC_WARN_ABOUT_MISSING_FIELD_INITIALIZERS = NO;
@@ -2136,6 +2142,7 @@
 				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
 				CLANG_WARN_STRICT_PROTOTYPES = YES;
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
+				EXCLUDED_ARCHS = x86_64;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = NO;
 				GCC_WARN_ABOUT_MISSING_FIELD_INITIALIZERS = NO;
diff --git a/script/update_libgit2 b/script/update_libgit2
index 3152c446..068d2fd1 100755
--- a/script/update_libgit2
+++ b/script/update_libgit2
@@ -2,6 +2,15 @@
 
 set -e
 
+product="External/libgit2.a"
+newer_source=$(find External/libgit2 \
+  \( -path 'External/libgit2/.git' -o -path 'External/libgit2/build' \) -prune -o \
+  -type f -newer "$product" -print -quit 2>/dev/null || true)
+if [ -f "$product" ] && [ -z "$newer_source" ]; then
+  echo "libgit2 is up to date."
+  exit 0
+fi
+
 cd "External/libgit2"
 
 if [ -d "build" ]; then
@@ -12,7 +21,7 @@ mkdir build
 cd build
 
 # OpenSSL is keg-only, so add its pkgconfig location manually
-if [[ $(uname -m) == 'arm64' ]]; then
+if [ "$(uname -m)" = 'arm64' ]; then
   echo "Running on a Apple Silicon M1"
   export ARCH_PREFIX=/opt/homebrew
 else