diff --git a/modules/openapi-generator/src/main/resources/Javascript/ApiClient.mustache b/modules/openapi-generator/src/main/resources/Javascript/ApiClient.mustache
index 47ec095c769..7fd5f5e6cec 100644
--- a/modules/openapi-generator/src/main/resources/Javascript/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/Javascript/ApiClient.mustache
@@ -459,8 +459,6 @@
       if(contentType != 'multipart/form-data') {
         request.type(contentType);
       }
-    } else if (!request.header['Content-Type']) {
-      request.type('application/json');
     }
 
     if (contentType === 'application/x-www-form-urlencoded') {
@@ -478,6 +476,9 @@
         }
       }
     } else if (bodyParam !== null && bodyParam !== undefined) {
+      if (!request.header['Content-Type']) {
+          request.type('application/json');
+      }
       request.send(bodyParam);
     }
 
diff --git a/modules/openapi-generator/src/main/resources/Javascript/es6/ApiClient.mustache b/modules/openapi-generator/src/main/resources/Javascript/es6/ApiClient.mustache
index f98d9fbf3e5..aa54b3d1bb8 100644
--- a/modules/openapi-generator/src/main/resources/Javascript/es6/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/Javascript/es6/ApiClient.mustache
@@ -421,8 +421,6 @@ class ApiClient {
             if(contentType != 'multipart/form-data') {
                 request.type(contentType);
             }
-        } else if (!request.header['Content-Type']) {
-            request.type('application/json');
         }
 
         if (contentType === 'application/x-www-form-urlencoded') {
@@ -440,6 +438,9 @@ class ApiClient {
                 }
             }
         } else if (bodyParam !== null && bodyParam !== undefined) {
+            if (!request.header['Content-Type']) {
+                request.type('application/json');
+            }
             request.send(bodyParam);
         }
 
diff --git a/samples/client/petstore/javascript-es6/src/ApiClient.js b/samples/client/petstore/javascript-es6/src/ApiClient.js
index 5d266cc248c..9d51da74d54 100644
--- a/samples/client/petstore/javascript-es6/src/ApiClient.js
+++ b/samples/client/petstore/javascript-es6/src/ApiClient.js
@@ -408,8 +408,6 @@ class ApiClient {
             if(contentType != 'multipart/form-data') {
                 request.type(contentType);
             }
-        } else if (!request.header['Content-Type']) {
-            request.type('application/json');
         }
 
         if (contentType === 'application/x-www-form-urlencoded') {
@@ -427,6 +425,9 @@ class ApiClient {
                 }
             }
         } else if (bodyParam !== null && bodyParam !== undefined) {
+            if (!request.header['Content-Type']) {
+                request.type('application/json');
+            }
             request.send(bodyParam);
         }
 
diff --git a/samples/client/petstore/javascript-promise-es6/src/ApiClient.js b/samples/client/petstore/javascript-promise-es6/src/ApiClient.js
index dc4ff806226..581711e0194 100644
--- a/samples/client/petstore/javascript-promise-es6/src/ApiClient.js
+++ b/samples/client/petstore/javascript-promise-es6/src/ApiClient.js
@@ -400,8 +400,6 @@ class ApiClient {
             if(contentType != 'multipart/form-data') {
                 request.type(contentType);
             }
-        } else if (!request.header['Content-Type']) {
-            request.type('application/json');
         }
 
         if (contentType === 'application/x-www-form-urlencoded') {
@@ -419,6 +417,9 @@ class ApiClient {
                 }
             }
         } else if (bodyParam !== null && bodyParam !== undefined) {
+            if (!request.header['Content-Type']) {
+                request.type('application/json');
+            }
             request.send(bodyParam);
         }
 
diff --git a/samples/client/petstore/javascript-promise/src/ApiClient.js b/samples/client/petstore/javascript-promise/src/ApiClient.js
index 634c1cc2cce..f227bc3543e 100644
--- a/samples/client/petstore/javascript-promise/src/ApiClient.js
+++ b/samples/client/petstore/javascript-promise/src/ApiClient.js
@@ -449,8 +449,6 @@
       if(contentType != 'multipart/form-data') {
         request.type(contentType);
       }
-    } else if (!request.header['Content-Type']) {
-      request.type('application/json');
     }
 
     if (contentType === 'application/x-www-form-urlencoded') {
@@ -468,6 +466,9 @@
         }
       }
     } else if (bodyParam !== null && bodyParam !== undefined) {
+      if (!request.header['Content-Type']) {
+          request.type('application/json');
+      }
       request.send(bodyParam);
     }
 
diff --git a/samples/client/petstore/javascript/src/ApiClient.js b/samples/client/petstore/javascript/src/ApiClient.js
index b86103b6baf..17f85b1e2c8 100644
--- a/samples/client/petstore/javascript/src/ApiClient.js
+++ b/samples/client/petstore/javascript/src/ApiClient.js
@@ -458,8 +458,6 @@
       if(contentType != 'multipart/form-data') {
         request.type(contentType);
       }
-    } else if (!request.header['Content-Type']) {
-      request.type('application/json');
     }
 
     if (contentType === 'application/x-www-form-urlencoded') {
@@ -477,6 +475,9 @@
         }
       }
     } else if (bodyParam !== null && bodyParam !== undefined) {
+      if (!request.header['Content-Type']) {
+          request.type('application/json');
+      }
       request.send(bodyParam);
     }
 
diff --git a/samples/openapi3/client/petstore/javascript-es6/src/ApiClient.js b/samples/openapi3/client/petstore/javascript-es6/src/ApiClient.js
index fc521813b36..83cba1cae1a 100644
--- a/samples/openapi3/client/petstore/javascript-es6/src/ApiClient.js
+++ b/samples/openapi3/client/petstore/javascript-es6/src/ApiClient.js
@@ -409,8 +409,6 @@ class ApiClient {
             if(contentType != 'multipart/form-data') {
                 request.type(contentType);
             }
-        } else if (!request.header['Content-Type']) {
-            request.type('application/json');
         }
 
         if (contentType === 'application/x-www-form-urlencoded') {
@@ -428,6 +426,9 @@ class ApiClient {
                 }
             }
         } else if (bodyParam !== null && bodyParam !== undefined) {
+            if (!request.header['Content-Type']) {
+                request.type('application/json');
+            }
             request.send(bodyParam);
         }