diff --git a/.travis.yml b/.travis.yml
index 0304eb54..68373b5d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,5 +15,5 @@ script:
   - travis_wait node $nflags packages/swagger2openapi/testRunner -q -l openapi-directory/APIs/
   - travis_wait node $nflags packages/swagger2openapi/testRunner -q openapi-definitions/
   - travis_wait node $nflags packages/swagger2openapi/testRunner -q -n openapi3-examples/pass
-  - travis_wait node $nflags packages/swagger2openapi/testRunner -q -r -n -f openapi3-examples/fail .
+  - travis_wait node $nflags packages/swagger2openapi/testRunner -q -r -n -f openapi3-examples/fail bin
   - node $nflags packages/swagger2openapi/testRunner -q -r test/s2o-test
diff --git a/packages/oas-validator/index.js b/packages/oas-validator/index.js
index 18706caa..aed3f9de 100644
--- a/packages/oas-validator/index.js
+++ b/packages/oas-validator/index.js
@@ -348,7 +348,9 @@ function checkContent(content, contextServers, openapi, options) {
     for (let ct in content) {
         contextAppend(options, jptr.jpescape(ct));
         // validate ct against https://tools.ietf.org/html/rfc6838#section-4.2
-        should(/[a-zA-Z0-9!#$%^&\*_\-\+{}\|'.`~]+\/[a-zA-Z0-9!#$%^&\*_\-\+{}\|'.`~]+/.test(ct)).be.exactly(true,'media-type should match RFC6838 format'); // this is a SHOULD not MUST
+        if (options.mediatype) {
+            should(/[a-zA-Z0-9!#$%^&\*_\-\+{}\|'.`~]+\/[a-zA-Z0-9!#$%^&\*_\-\+{}\|'.`~]+/.test(ct)).be.exactly(true,'media-type should match RFC6838 format'); // this is a SHOULD not MUST
+        }
         let contentType = content[ct];
         should(contentType).be.an.Object();
         should(contentType).not.be.an.Array();
diff --git a/packages/swagger2openapi/README.md b/packages/swagger2openapi/README.md
index 2f46c0a9..38790faf 100644
--- a/packages/swagger2openapi/README.md
+++ b/packages/swagger2openapi/README.md
@@ -92,6 +92,7 @@ Options:
   -f, --fail        path to specs expected to fail                      [string]
   -j, --jsonschema  path to alternative JSON schema                     [string]
   -l, --laxurls     lax checking of empty urls                         [boolean]
+  -m, --mediatype   check media-types against RFC pattern              [boolean]
   -n, --nopatch     do not patch minor errors in the source definition [boolean]
   -o, --output      output conversion result  [string] [default: "openapi.yaml"]
   -q, --quiet       do not show test passes on console, for CI         [boolean]
diff --git a/packages/swagger2openapi/docs/options.md b/packages/swagger2openapi/docs/options.md
index 50ffc6dd..80385e04 100644
--- a/packages/swagger2openapi/docs/options.md
+++ b/packages/swagger2openapi/docs/options.md
@@ -21,6 +21,7 @@ indent|String|Input|Command-line flag to control JSON indenting
 jsonschema|String|Input|Path to alternative JSON schema (in JSON or YAML) for validation
 laxRefs|Boolean|Input|**No longer has any effect as this is now the default**
 laxurls|Boolean|Input|Flag to validation step to ignore empty URLs
+mediatype|Boolean|Input|Flag to validation step to check media-type strings against RFC pattern
 nopatch|Boolean|Input|Command-line flag by `testRunner` to unset `patch`
 openapi|Object|Output|The OpenApi 3.x definition returned from a conversion step
 operationIds|Array[string]|Output|Used by validation to track uniqueness of operationIds
diff --git a/packages/swagger2openapi/testRunner.js b/packages/swagger2openapi/testRunner.js
index 5bae9ceb..c091bf74 100755
--- a/packages/swagger2openapi/testRunner.js
+++ b/packages/swagger2openapi/testRunner.js
@@ -35,6 +35,9 @@ let argv = yargs
     .boolean('laxurls')
     .alias('l', 'laxurls')
     .describe('laxurls', 'lax checking of empty urls')
+    .boolean('mediatype')
+    .alias('m','mediatype')
+    .describe('mediatype','check media-types against RFC pattern')
     .boolean('lint')
     .describe('lint','lint the definition')
     .boolean('nopatch')