diff --git a/Makefile b/Makefile
index 6f3e624..5db53ae 100644
--- a/Makefile
+++ b/Makefile
@@ -1,47 +1,69 @@
 # Makefile for phbar
 #
 # Usage: make <target>
+#
+# NOTE: Never invoke this Makefile with `sudo` (e.g. `sudo make install`).
+# Running `swift build` as root corrupts `.build/` with root-owned files that
+# break subsequent non-root builds (you get "invalid access to …/DerivedSources").
+# The `install`/`uninstall` targets elevate *only* the file copy, and only when
+# the destination is not user-writable, so `sudo` is never needed from the user.
 
-BIN_DIR := /usr/local/bin
+# Install directory. Override with: make install BIN_DIR=/opt/homebrew/bin
+BIN_DIR ?= /usr/local/bin
 BUILD_DIR := .build/release
 BINARIES := phbar
 
-.PHONY: all build install clean test run
+# Guard: any target that runs Swift must not run under sudo, otherwise it would
+# sprinkle root-owned files across .build/. It fails fast with a helpful message
+# instead of corrupting the build directory. Recursively-expanded (`=`) so that
+# the `$@` automatic variable resolves per-target at recipe time.
+guard_not_root = @if [ "$$(id -u)" = "0" ] && [ -n "$$SUDO_USER" ]; then \
+	echo "❌ 'make $@' must not run under sudo (it would corrupt .build/)." >&2; \
+	echo "   Run 'make install' without sudo; it elevates only the copy step." >&2; \
+	exit 1; \
+fi
+
+.PHONY: all build install clean test run uninstall reinstall help
 
 all: build
 
 # Build all targets in release mode
 build:
+	$(guard_not_root)
 	swift build -c release
 
-# Build and install binaries to /usr/local/bin
+# Build and install binaries. Elevates only the copy when BIN_DIR isn't writable.
 install: build
 	@mkdir -p $(BIN_DIR)
-	@for bin in $(BINARIES); do \
-		cp -f $(BUILD_DIR)/$$bin $(BIN_DIR)/; \
-		done
+	@if [ -w "$(BIN_DIR)" ]; then CP="cp -f"; else CP="sudo cp -f"; fi; \
+	for bin in $(BINARIES); do \
+		$$CP $(BUILD_DIR)/$$bin $(BIN_DIR)/; \
+	done
 	@echo "✅ Installed $(BINARIES) to $(BIN_DIR)"
 
 # Clean build artifacts
 clean:
+	$(guard_not_root)
 	swift package clean
 
 # Run tests
 test:
+	$(guard_not_root)
 	swift test
 
 # Quick test: build, install, and verify
 run: install
 	@echo "Verifying installation..."
 	@for bin in $(BINARIES); do \
-		which $$bin > /dev/null && echo "✓ $$bin: $(shell which $$bin)" || echo "✗ $$bin: not found"; \
+		which $$bin > /dev/null && echo "✓ $$bin: $$($$bin --version 2>/dev/null | head -1)" || echo "✗ $$bin: not found"; \
 		done
 
-# Uninstall binaries from /usr/local/bin
+# Uninstall binaries. Elevates only the remove when BIN_DIR isn't writable.
 uninstall:
-	@for bin in $(BINARIES); do \
-		rm -f $(BIN_DIR)/$$bin; \
-		done
+	@if [ -w "$(BIN_DIR)" ]; then RM="rm -f"; else RM="sudo rm -f"; fi; \
+	for bin in $(BINARIES); do \
+		$$RM $(BIN_DIR)/$$bin; \
+	done
 	@echo "✅ Uninstalled $(BINARIES) from $(BIN_DIR)"
 
 # Rebuild and reinstall (clean + install)
@@ -51,9 +73,12 @@ reinstall: clean install
 help:
 	@echo "Available targets:"
 	@echo "  make build       - Build in release mode"
-	@echo "  make install     - Build and install to /usr/local/bin"
+	@echo "  make install     - Build and install to $(BIN_DIR)"
 	@echo "  make clean       - Clean build artifacts"
 	@echo "  make test        - Run tests"
 	@echo "  make run         - Build, install, and verify"
-	@echo "  make uninstall   - Remove binaries from /usr/local/bin"
+	@echo "  make uninstall   - Remove binaries from $(BIN_DIR)"
 	@echo "  make reinstall   - Clean and reinstall"
+	@echo ""
+	@echo "Override the install location with BIN_DIR, e.g.:"
+	@echo "  make install BIN_DIR=$(HOME)/.local/bin"