diff --git a/index.js b/index.js
index d90122c..be19872 100644
--- a/index.js
+++ b/index.js
@@ -1,5 +1,6 @@
 exports.all          = require('./lib/all')
 exports.assign       = require('./lib/assign')
+exports.assignP      = require('./lib/assignP')
 exports.backoff      = require('./lib/backoff')
 exports.combine      = require('./lib/combine')
 exports.combineAll   = require('./lib/combineAll')
diff --git a/src/assignP.js b/src/assignP.js
new file mode 100644
index 0000000..b59dd83
--- /dev/null
+++ b/src/assignP.js
@@ -0,0 +1,9 @@
+const curry        = require('ramda/src/curry')
+const combineWithP = require('./combineWithP')
+const put          = require('./put')
+
+// assignP : String -> ({ k: v } -> Promise a) -> Promise { k: v }
+const assignP = (key, fn) =>
+  combineWithP(put(key), fn)
+
+module.exports = curry(assignP)
diff --git a/test/assignP.js b/test/assignP.js
new file mode 100644
index 0000000..570eaa9
--- /dev/null
+++ b/test/assignP.js
@@ -0,0 +1,19 @@
+const { expect } = require('chai')
+const property   = require('prop-factory')
+const always     = require('ramda/src/always')
+
+const { assignP } = require('..')
+
+const assigner = assignP('foo', always(Promise.resolve('bar')))
+
+describe('assignP', () => {
+  const res = property()
+
+  beforeEach(() =>
+    assigner({}).then(res)
+  )
+
+  it('sets the foo property to the result of the function', () =>
+    expect(res()).to.eql({ foo: 'bar' })
+  )
+})