diff --git a/.circleci/config.yml b/.circleci/config.yml
index 0018583..2798c19 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -10,10 +10,10 @@ jobs:
       - checkout
       - restore_cache:
           key: next-jdbc-{{ checksum "deps.edn" }}
-      - run: clojure -P -A:test
+      - run: clojure -P -M:build:test
       - save_cache:
           paths:
             - ~/.m2
             - ~/.gitlibs
           key: next-jdbc-{{ checksum "deps.edn" }}
-      - run: clojure -X:test
+      - run: clojure -T:build ci
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 2dbf790..b903abf 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -19,7 +19,7 @@ jobs:
         with:
           tools-deps: '1.10.3.933'
       - name: Run Tests
-        run: clojure -X:test
+        run: clojure -T:build ci
 
   build-graalvm-old:
     runs-on: ubuntu-latest
@@ -39,7 +39,7 @@ jobs:
         with:
           tools-deps: '1.10.3.933'
       - name: Run Tests
-        run: clojure -X:test
+        run: clojure -T:build ci
 
   build-graalvm-new:
     runs-on: ubuntu-latest
@@ -59,4 +59,4 @@ jobs:
         with:
           tools-deps: '1.10.3.933'
       - name: Run Tests
-        run: clojure -X:test
+        run: clojure -T:build ci
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 741cdba..e1c6ac0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 Only accretive/fixative changes will be made from now on.
 
+* 1.2.next in progress
+  * Switch to `tools.build` for running tests and JAR building etc.
+
 * 1.2.689 -- 2021-08-01
   * Address #173 by extending `DatafiableRow` to `ResultSet` so there's a public method to call on (rows of) a JDBC result set directly.
   * Address #171 by clarifying that you cannot use `clojure.java.jdbc` functions inside `next.jdbc/with-transaction` and discuss how to migrate transaction-based code in the **Migration** guide.
diff --git a/build.clj b/build.clj
index 3473fbe..94c1e79 100644
--- a/build.clj
+++ b/build.clj
@@ -1,4 +1,13 @@
 (ns build
+  "next.jdbc's build script.
+
+  clojure -T:build run-tests
+
+  clojure -T:build ci
+
+  For more information, run:
+
+  clojure -A:deps -T:build help/doc"
   (:require [clojure.tools.build.api :as b]
             [clojure.tools.deps.alpha :as t]))
 
@@ -8,11 +17,11 @@
 (def basis (b/create-basis {:project "deps.edn"}))
 (def jar-file (format "target/%s-%s.jar" (name lib) version))
 
-(defn clean [_]
+(defn clean "Remove the target folder." [_]
   (println "\nCleaning target...")
   (b/delete {:path "target"}))
 
-(defn jar [_]
+(defn jar "Build the library JAR file." [_]
   (println "\nWriting pom.xml...")
   (b/write-pom {:class-dir class-dir
                 :lib lib
@@ -26,8 +35,7 @@
   (b/jar {:class-dir class-dir
           :jar-file jar-file}))
 
-(defn run-tests
-  [_]
+(defn run-tests "Run regular tests." [_]
   (let [basis    (b/create-basis {:aliases [:test]})
         combined (t/combine-aliases basis [:test])
         cmds     (b/java-command {:basis     basis
@@ -38,5 +46,5 @@
     (when-not (zero? exit)
       (throw (ex-info "Tests failed" {})))))
 
-(defn ci [opts]
+(defn ci "Run the CI pipeline of tests (and build the JAR)." [opts]
   (-> opts (run-tests) (clean) (jar)))
diff --git a/deps.edn b/deps.edn
index cddf73d..d0236dc 100644
--- a/deps.edn
+++ b/deps.edn
@@ -4,8 +4,11 @@
 
         camel-snake-kebab/camel-snake-kebab {:mvn/version "0.4.2"}}
  :aliases
- {:build {:deps {io.github.clojure/tools.build {:git/tag "v0.1.7" :git/sha "8a3abc2"}}
+ {;; for help: clojure -A:deps -T:build help/doc
+  :build {:deps {io.github.clojure/tools.build {:git/tag "v0.1.7" :git/sha "8a3abc2"}}
           :ns-default build}
+
+  ;; running tests/checks of various kinds:
   :test {:extra-paths ["test"]
          :extra-deps {org.clojure/test.check {:mvn/version "1.1.0"}
                       io.github.cognitect-labs/test-runner
@@ -40,10 +43,15 @@
                       org.apache.logging.log4j/log4j-jul {:mvn/version "2.14.1"}
                       org.apache.logging.log4j/log4j-slf4j-impl {:mvn/version "2.14.1"}}
          :jvm-opts ["-Dlog4j2.configurationFile=log4j2-info.properties"]
-         :exec-fn cognitect.test-runner.api/test}
+         ;; so we can run both ways:
+         :exec-fn cognitect.test-runner.api/test
+         :main-opts ["-m" "cognitect.test-runner"]}
+
+  ;; first run: clojure -T:build ci
+  ;; then: clojure -T:deploy target/n<TAB>
   :deploy
-  {:replace-deps {slipset/deps-deploy {:git/url "https://github.com/slipset/deps-deploy"
-                                       :sha "b4359c5d67ca002d9ed0c4b41b710d7e5a82e3bf"}}
+  {:deps {slipset/deps-deploy {:git/url "https://github.com/slipset/deps-deploy"
+                               :sha "b4359c5d67ca002d9ed0c4b41b710d7e5a82e3bf"}}
    :exec-fn deps-deploy.deps-deploy/deploy
    :exec-args {:installer :remote
                :pom-file "target/classes/META-INF/maven/com.github.seancorfield/next.jdbc/pom.xml"}}}}