diff --git a/Makefile b/Makefile
index dfa6462..5154ef1 100644
--- a/Makefile
+++ b/Makefile
@@ -79,6 +79,13 @@ GRAV_CONTAINER ?= intotheeast_grav
 GRAV_PORT      ?= 8081
 TM_PORT        ?= 8082
 
+# The container boots as root (the base image entrypoint needs it to bind :80
+# and set up cron), so a bare `docker exec` runs as root and any file it writes
+# into the ./user bind mount is root-owned on the host. Run the file-CREATING
+# CLI commands as the host user instead, so their output belongs to you.
+HOST_UID := $(shell id -u)
+HOST_GID := $(shell id -g)
+
 build:
 	docker compose build
 
@@ -108,7 +115,12 @@ fix-perms:
 
 
 install-plugins:
-	docker exec -w /var/www/html $(GRAV_CONTAINER) php bin/gpm install $(shell cat plugins.txt | tr '\n' ' ') -y
+	# cache/ and tmp/ are root-owned in the image, so make them writable first
+	# (container-internal chown — never touches the host) so gpm can run AS YOU.
+	docker exec $(GRAV_CONTAINER) chown -R $(HOST_UID):$(HOST_GID) /var/www/html/cache /var/www/html/tmp
+	# gpm runs as the host user, so the plugins it writes into ./user/plugins are
+	# owned by you, not root — no post-hoc chown, no root files to clean up later.
+	docker exec -u $(HOST_UID):$(HOST_GID) -w /var/www/html $(GRAV_CONTAINER) php bin/gpm install $(shell cat plugins.txt | tr '\n' ' ') -y
 	$(MAKE) apply-plugin-patches
 
 # Re-apply local fixes to git-ignored, GPM-managed third-party plugins. Run this