diff --git a/config/test.js b/config/test.js
index b1b0fd4..6881bf6 100644
--- a/config/test.js
+++ b/config/test.js
@@ -57,30 +57,22 @@ function makeTasks(mode /*: "BASIC" | "FULL" */) {
     },
     {
       id: "check-pretty",
-      cmd: ["npm", "run", "--silent", "check-pretty"],
+      cmd: ["yarn", "run", "--silent", "check-pretty"],
       deps: [],
     },
     {
       id: "lint",
-      cmd: ["npm", "run", "--silent", "lint"],
+      cmd: ["yarn", "run", "--silent", "lint"],
       deps: [],
     },
     {
       id: "flow",
-      cmd: [
-        "npm",
-        "run",
-        "--silent",
-        "flow",
-        "--",
-        "--quiet",
-        "--max-warnings=0",
-      ],
+      cmd: ["yarn", "run", "--silent", "flow", "--quiet", "--max-warnings=0"],
       deps: [],
     },
     {
       id: "unit",
-      cmd: ["npm", "run", "--silent", "unit", "--", "--ci", "--maxWorkers=4"],
+      cmd: ["yarn", "run", "--silent", "unit", "--ci", "--maxWorkers=4"],
       deps: [],
     },
     {
@@ -91,11 +83,10 @@ function makeTasks(mode /*: "BASIC" | "FULL" */) {
     {
       id: "backend",
       cmd: [
-        "npm",
+        "yarn",
         "run",
         "--silent",
         "backend",
-        "--",
         "--output-path",
         backendOutput,
       ],
@@ -104,7 +95,7 @@ function makeTasks(mode /*: "BASIC" | "FULL" */) {
     {
       id: {BASIC: "sharness", FULL: "sharness-full"}[mode],
       cmd: withSourcecredBinEnv([
-        "npm",
+        "yarn",
         "run",
         "--silent",
         {BASIC: "sharness", FULL: "sharness-full"}[mode],
diff --git a/package.json b/package.json
index d397f02..1c7e443 100644
--- a/package.json
+++ b/package.json
@@ -71,7 +71,7 @@
     "unit": "BABEL_ENV=test NODE_ENV=test jest --env=jsdom",
     "sharness": "make -sC ./sharness prove PROVE_OPTS=-f TEST_OPTS='--chain-lint'",
     "sharness-full": "make -sC ./sharness prove PROVE_OPTS=-vf TEST_OPTS='-v --chain-lint --long'",
-    "coverage": "npm run unit -- --coverage",
+    "coverage": "yarn run unit --coverage",
     "flow": "flow",
     "lint": "eslint src config --max-warnings 0"
   },