diff --git a/CMakeLists.txt b/CMakeLists.txt
index 69b3e3f..b281905 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,6 +17,12 @@ if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
         "Build type (Debug, Release, RelWithDebInfo, MinSizeRel)" FORCE)
 endif()
 
+# Remember whether the user picked an install prefix *before* ECM's
+# KDECMakeSettings runs: that module resets an unspecified prefix back to
+# /usr/local, so we cannot rely on CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT
+# after including it. We re-apply the user-local default below, post-include.
+set(_deft_prefix_was_default ${CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT})
+
 find_package(ECM ${KF_MIN_VERSION} REQUIRED NO_MODULE)
 list(APPEND CMAKE_MODULE_PATH ${ECM_MODULE_PATH})
 
@@ -24,12 +30,30 @@ include(KDEInstallDirs)
 include(KDECMakeSettings)
 include(KDECompilerSettings NO_POLICY_SCOPE)
 
+# Default to a user-local install prefix when the user did not pick one. These
+# are user KTextEditor plugins, not system packages: the stock /usr/local
+# default needs root and is the wrong place for them. Applied here, after
+# KDECMakeSettings, so it is not clobbered.
+if(_deft_prefix_was_default)
+    set(CMAKE_INSTALL_PREFIX "$ENV{HOME}/.local" CACHE PATH "Install prefix" FORCE)
+endif()
+
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 find_package(Qt6 ${QT_MIN_VERSION} REQUIRED COMPONENTS Core Gui Widgets Concurrent)
 find_package(Qt6 ${QT_MIN_VERSION} COMPONENTS Test)
 find_package(KF6 ${KF_MIN_VERSION} COMPONENTS TextEditor XmlGui CoreAddons I18n)
 
+# KDE's KDE_INSTALL_PLUGINDIR defaults to lib/<arch>/plugins/, but Qt6 plugins
+# (which is where Kate scans for KTextEditor plugins) live under
+# lib/<arch>/qt6/plugins/. Point the plugin install base at Qt's own plugin
+# dir (QT6_INSTALL_PLUGINS is prefix-relative) so
+# kcoreaddons_add_plugin(INSTALL_NAMESPACE kf6/ktexteditor) lands where Kate
+# actually looks. kcoreaddons_add_plugin reads the *normal* variable, so set
+# it directly (not just the cache entry, which the normal value would shadow).
+set(KDE_INSTALL_PLUGINDIR "${QT6_INSTALL_PLUGINS}")
+set(KDE_INSTALL_PLUGINDIR "${QT6_INSTALL_PLUGINS}" CACHE PATH "" FORCE)
+
 enable_testing()
 
 add_subdirectory(src)
diff --git a/README.md b/README.md
index 941fbbb..fd894f2 100644
--- a/README.md
+++ b/README.md
@@ -65,13 +65,28 @@ KTextEditor plugins under `build/bin/kf6/ktexteditor/`:
 | `deft_sam.so`    | `[deft:nineify] sam`  | `sam`-style structural regular expressions |
 | `deft_plumb.so`  | `[deft:nineify] plumb`| Plan 9 plumber (open under cursor) |
 
-Drop whichever features you want where Kate scans for KTextEditor plugins (a
-user path on `QT_PLUGIN_PATH`):
+Drop whichever features you want where Kate scans for KTextEditor plugins. The
+simplest way is `cmake --install`, which already targets the right place:
 
 ```sh
-for so in build/bin/kf6/ktexteditor/deft_*.so; do
-  install -D "$so" ~/.local/lib/x86_64-linux-gnu/qt6/plugins/kf6/ktexteditor/"$(basename "$so")"
-done
+cmake --install build
+```
+
+**By default this installs into your home directory, not system-wide.** The
+build sets `CMAKE_INSTALL_PREFIX` to `~/.local` when you don't pass one (these
+are personal plugins, so installing them under `/usr/local` — the stock CMake
+default — would need `root` and is the wrong place), and it points the plugin
+install dir at Qt's own plugin path. So the plugins land at:
+
+```
+~/.local/lib/<arch>/qt6/plugins/kf6/ktexteditor/deft_*.so
+```
+
+which is exactly the directory Kate scans (`QT_PLUGIN_PATH`). To install
+system-wide instead, pass an explicit prefix (and expect to need `root`):
+
+```sh
+cmake --install build --prefix /usr
 ```
 
 Then in Kate: Settings → Configure Kate → Plugins → enable each **`[deft:…]`**