diff --git a/lib/Adaptor.js b/lib/Adaptor.js
index 592cc70..011c3fc 100644
--- a/lib/Adaptor.js
+++ b/lib/Adaptor.js
@@ -226,8 +226,13 @@ function post(path, params, callback) {
     const config = (0, _Utils.mapToAxiosConfig)({ ...params,
       url,
       auth
-    });
-    return _languageCommon.http.post(config)(state).then(response => {
+    }); // NOTE: that in order to use multipart/form submissions, we call axios.post
+    // directly so as to avoid calling 'expandReferences' on the config (in
+    // language-common.http.post) once we've set up the 'form-data' module.
+    // Elsewhere, calling expandReferences multiple times is harmless.
+
+    return axios.post(config.url, config.data, { ...config
+    }).then(response => {
       const nextState = (0, _languageCommon.composeNextState)(state, response.data);
       if (callback) return callback(nextState);
       return nextState;
diff --git a/src/Adaptor.js b/src/Adaptor.js
index c9de949..4a70732 100644
--- a/src/Adaptor.js
+++ b/src/Adaptor.js
@@ -162,13 +162,15 @@ export function post(path, params, callback) {
 
     const config = mapToAxiosConfig({ ...params, url, auth });
 
-    return http
-      .post(config)(state)
-      .then(response => {
-        const nextState = composeNextState(state, response.data);
-        if (callback) return callback(nextState);
-        return nextState;
-      });
+    // NOTE: that in order to use multipart/form submissions, we call axios.post
+    // directly so as to avoid calling 'expandReferences' on the config (in
+    // language-common.http.post) once we've set up the 'form-data' module.
+    // Elsewhere, calling expandReferences multiple times is harmless.
+    return axios.post(config.url, config.data, { ...config }).then(response => {
+      const nextState = composeNextState(state, response.data);
+      if (callback) return callback(nextState);
+      return nextState;
+    });
   };
 }
 
diff --git a/test/index.js b/test/index.js
index a5a09cc..d61c3a4 100644
--- a/test/index.js
+++ b/test/index.js
@@ -453,10 +453,10 @@ describe('post', () => {
     )(state);
 
     expect(finalState.data.body).to.contain(
-      'Content-Disposition: form-data; name="username"\r\n\r\n'
+      'Content-Disposition: form-data; name="username"\r\n\r\nfake'
     );
     expect(finalState.data.body).to.contain(
-      'Content-Disposition: form-data; name="password"\r\n\r\n'
+      'Content-Disposition: form-data; name="password"\r\n\r\nfake_pass'
     );
   });
 
@@ -482,10 +482,13 @@ describe('post', () => {
     )(state);
 
     expect(finalState.data.body).to.contain(
-      'Content-Disposition: form-data; name="username"\r\n\r\n'
+      'Content-Disposition: form-data; name="id"\r\n\r\nfake_id'
     );
     expect(finalState.data.body).to.contain(
-      'Content-Disposition: form-data; name="password"\r\n\r\n'
+      'Content-Disposition: form-data; name="parent"\r\n\r\nfake_parent'
+    );
+    expect(finalState.data.body).to.contain(
+      'Content-Disposition: form-data; name="mobile_phone"\r\n\r\nfake_phone'
     );
   });