diff --git a/src/execute.js b/src/execute.js
index 78f23c92f..0d5d4cdda 100644
--- a/src/execute.js
+++ b/src/execute.js
@@ -93,10 +93,6 @@ export function buildRequest({
     req.headers.accept = responseContentType
   }
 
-  if (requestContentType) {
-    req.headers['content-type'] = requestContentType
-  }
-
   // Add values to request
   arrayOrEmpty(operation.parameters) // operation parameters
     .concat(arrayOrEmpty(spec.paths[pathName].parameters)) // path parameters
@@ -127,6 +123,20 @@ export function buildRequest({
   req = applySecurities({request: req, securities, operation, spec})
   // Will add the query object into the URL, if it exists
   mergeInQueryOrForm(req)
+
+  if (req.body || req.form) {
+    if (requestContentType) {
+      req.headers['content-type'] = requestContentType
+    } else if (Array.isArray(operation.consumes)) {
+      req.headers['content-type'] = operation.consumes[0]
+    } else if (Array.isArray(spec.consumes)) {
+      req.headers['content-type'] = spec.consumes[0]
+    } else if (operation.parameters.filter((p)=> p.type === "file").length) {
+      req.headers['content-type'] = "multipart/form-data"
+    } else if (operation.parameters.filter((p)=> p.in === "formData").length) {
+      req.headers['content-type'] = "application/x-www-form-urlencoded"
+    }
+  }
   return req
 }
 
diff --git a/test/execute.js b/test/execute.js
index 30ee60613..71f6998e3 100644
--- a/test/execute.js
+++ b/test/execute.js
@@ -441,7 +441,7 @@ describe('execute', () => {
       })
     })
 
-    it('should handle requestContentType', function () {
+    it('should not add content-type with no form-data or body param', function () {
       // Given
       const spec = {
         host: 'swagger.io',
@@ -454,14 +454,143 @@ describe('execute', () => {
       // Then
       expect(req).toEqual({
         url: 'http://swagger.io/one',
-        headers: {
-          'content-type': 'application/josh',
-        },
+        headers: {},
         credentials: 'same-origin',
         method: 'GET'
       })
     })
 
+    it('should add content-type multipart/form-data when param type is file and no other sources of consumes', function () {
+      // Given
+      const spec = {
+        host: 'swagger.io',
+        paths: {
+          '/one': {
+            post: {
+              operationId: 'postMe',
+              parameters: [{name: 'file', type: 'file', 'in': "formData"}]
+            }
+          }
+        }
+      }
+
+      // When
+      const req = buildRequest({
+        spec,
+        operationId: 'postMe',
+        parameters: { file: 'test'}})
+
+      // Then
+      expect(req).toEqual({
+        method: "POST",
+        "body": "file=test",
+        url: 'http://swagger.io/one',
+        headers: {
+          "content-type": "multipart/form-data"
+        },
+        credentials: 'same-origin'
+      })
+    })
+
+    it('should add content-type application/x-www-form-urlencoded when in: formData ', function () {
+      // Given
+      const spec = {
+        host: 'swagger.io',
+        paths: {
+          '/one': {
+            post: {
+              operationId: 'postMe',
+              parameters: [{name: 'file', in: 'formData'}]
+            }
+          }
+        }
+      }
+
+      // When
+      const req = buildRequest({
+        spec,
+        operationId: 'postMe',
+        parameters: { file: 'test'}})
+
+      // Then
+      expect(req).toEqual({
+        body: "file=test",
+        method: "POST",
+        url: 'http://swagger.io/one',
+        headers: {
+          "content-type": "application/x-www-form-urlencoded"
+        },
+        credentials: 'same-origin'
+      })
+    })
+
+    it('should add content-type from spec when no consumes in operation and no requestContentType passed', function () {
+      // Given
+      const spec = {
+        host: 'swagger.io',
+        consumes: ["test"],
+        paths: {
+          '/one': {
+            post: {
+              operationId: 'postMe',
+              parameters: [{name: 'file', in: 'formData'}]
+            }
+          }
+        }
+      }
+
+      // When
+      const req = buildRequest({
+        spec,
+        operationId: 'postMe',
+        parameters: { file: 'test'}})
+
+      // Then
+      expect(req).toEqual({
+        body: "file=test",
+        method: "POST",
+        url: 'http://swagger.io/one',
+        headers: {
+          "content-type": "test"
+        },
+        credentials: 'same-origin'
+      })
+    })
+
+    it('should add content-type from operation when no requestContentType passed', function () {
+      // Given
+      const spec = {
+        host: 'swagger.io',
+        consumes: ["no"],
+        paths: {
+          '/one': {
+            post: {
+              operationId: 'postMe',
+              consumes: ["test"],
+              parameters: [{name: 'file', in: 'formData'}]
+            }
+          }
+        }
+      }
+
+      // When
+      const req = buildRequest({
+        spec,
+        operationId: 'postMe',
+        parameters: { file: 'test'}})
+
+      // Then
+      expect(req).toEqual({
+        body: "file=test",
+        method: "POST",
+        url: 'http://swagger.io/one',
+        headers: {
+          "content-type": "test"
+        },
+        credentials: 'same-origin'
+      })
+    })
+
     it('should build a request for all given fields', function () {
       // Given
       const spec = {