diff --git a/src/plugins/json.js b/src/plugins/json.js
index 7155ad74..ca1e6f24 100644
--- a/src/plugins/json.js
+++ b/src/plugins/json.js
@@ -11,7 +11,7 @@ export default function plugin(formidable, options) {
   /* istanbul ignore next */
   const self = this || formidable;
 
-  if (/json/i.test(self.headers['content-type'])) {
+  if (/^[^;]*json/i.test(self.headers['content-type'])) {
     init.call(self, self, options);
   }
 
diff --git a/src/plugins/multipart.js b/src/plugins/multipart.js
index eebd96a7..b87f8235 100644
--- a/src/plugins/multipart.js
+++ b/src/plugins/multipart.js
@@ -15,7 +15,7 @@ export default function plugin(formidable, options) {
   const self = this || formidable;
 
   // NOTE: we (currently) support both multipart/form-data and multipart/related
-  const multipart = /multipart/i.test(self.headers['content-type']);
+  const multipart = /^[^;]*multipart/i.test(self.headers['content-type']);
 
   if (multipart) {
     const m = self.headers['content-type'].match(
diff --git a/src/plugins/octetstream.js b/src/plugins/octetstream.js
index 0bc5c67e..486e332a 100644
--- a/src/plugins/octetstream.js
+++ b/src/plugins/octetstream.js
@@ -11,7 +11,7 @@ export default async function plugin(formidable, options) {
   /* istanbul ignore next */
   const self = this || formidable;
 
-  if (/octet-stream/i.test(self.headers['content-type'])) {
+  if (/^[^;]*octet-stream/i.test(self.headers['content-type'])) {
     await init.call(self, self, options);
   }
   return self;
diff --git a/src/plugins/querystring.js b/src/plugins/querystring.js
index ef435aa7..73113bce 100644
--- a/src/plugins/querystring.js
+++ b/src/plugins/querystring.js
@@ -12,7 +12,7 @@ export default function plugin(formidable, options) {
   /* istanbul ignore next */
   const self = this || formidable;
 
-  if (/urlencoded/i.test(self.headers['content-type'])) {
+  if (/^[^;]*urlencoded/i.test(self.headers['content-type'])) {
     init.call(self, self, options);
   }
   return self;
diff --git a/test/fixture/http/misc/boundary-substring-json.http b/test/fixture/http/misc/boundary-substring-json.http
new file mode 100644
index 00000000..09e0601b
--- /dev/null
+++ b/test/fixture/http/misc/boundary-substring-json.http
@@ -0,0 +1,13 @@
+POST /upload HTTP/1.1
+Host: localhost:8080
+Content-Type: multipart/form-data; boundary=uj05Dyqd7Fd5aqAJnK1j9WeJSONmNy5vSGbM1oLf
+Content-Length: 211
+
+--uj05Dyqd7Fd5aqAJnK1j9WeJSONmNy5vSGbM1oLf
+Content-Disposition: form-data; filename="plain.txt"; name="upload"
+Content-Type: text/plain
+
+I am a plain text file
+
+--uj05Dyqd7Fd5aqAJnK1j9WeJSONmNy5vSGbM1oLf--
+
diff --git a/test/fixture/js/misc.js b/test/fixture/js/misc.js
index 80e36eab..31cf174e 100644
--- a/test/fixture/js/misc.js
+++ b/test/fixture/js/misc.js
@@ -1,3 +1,12 @@
+const boundary_substring_json = [
+  {
+    type: 'file',
+    name: 'upload',
+    originalFilename: 'plain.txt',
+    fixture: 'boundary-substring-json',
+  },
+];
+
 const empty_http = [];
 const empty_urlencoded_http = [];
 const empty_multipart_http = [];
@@ -5,6 +14,7 @@ const empty_multipart2_http = [];
 const _minimal_http = [];
 
 export {
+  boundary_substring_json,
   empty_http,
   empty_urlencoded_http,
   empty_multipart_http,
diff --git a/test/integration/fixtures.test.js b/test/integration/fixtures.test.js
index a37840c0..9269ab90 100644
--- a/test/integration/fixtures.test.js
+++ b/test/integration/fixtures.test.js
@@ -58,30 +58,36 @@ test('fixtures', (done) => {
     const fixture = fixtureWithName.fixture;
 
     uploadFixture(fixtureName, (err, parts) => {
-      if (err) {
-        err.fixtureName = fixtureName;
-        throw err;
-      }
+      try {
+        if (err) {
+          err.fixtureName = fixtureName;
+          throw err;
+        }
 
-      fixture.forEach((expectedPart, i) => {
-        const parsedPart = parts[i];
-        strictEqual(parsedPart.type, expectedPart.type);
-        strictEqual(parsedPart.name, expectedPart.name);
-
-        if (parsedPart.type === 'file') {
-          const file = parsedPart.value;
-          strictEqual(file.originalFilename, expectedPart.originalFilename,
-            `${JSON.stringify([expectedPart, file])}`);
-
-          if (expectedPart.sha1) {
-            strictEqual(
-              file.hash,
-              expectedPart.sha1,
-              `SHA1 error ${file.originalFilename} on ${file.filepath} ${JSON.stringify([expectedPart, file])}`,
-            );
+        fixture.forEach((expectedPart, i) => {
+          const parsedPart = parts[i];
+          strictEqual(parsedPart.type, expectedPart.type);
+          strictEqual(parsedPart.name, expectedPart.name);
+
+          if (parsedPart.type === 'file') {
+            const file = parsedPart.value;
+            strictEqual(file.originalFilename, expectedPart.originalFilename,
+              `${JSON.stringify([expectedPart, file])}`);
+
+            if (expectedPart.sha1) {
+              strictEqual(
+                file.hash,
+                expectedPart.sha1,
+                `SHA1 error ${file.originalFilename} on ${file.filepath} ${JSON.stringify([expectedPart, file])}`,
+              );
+            }
           }
-        }
-      });
+        });
+      } catch (e) {
+        server.close();
+        done(e);
+        throw e;
+      }
 
       testNext(results);
     });
@@ -93,7 +99,6 @@ test('fixtures', (done) => {
         uploadDir: UPLOAD_DIR,
         hashAlgorithm: 'sha1',
       });
-      form.parse(req);
 
       function callback(...args) {
         const realCallback = cb;
@@ -116,6 +121,8 @@ test('fixtures', (done) => {
           res.end();
           callback(null, parts);
         });
+
+      form.parse(req);
     });
 
     const socket = createConnection(PORT);