diff --git a/modules/openapi-generator/src/main/resources/typescript-fetch/runtime.mustache b/modules/openapi-generator/src/main/resources/typescript-fetch/runtime.mustache
index ee1ee65cc393..767a34880808 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/runtime.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/runtime.mustache
@@ -50,7 +50,7 @@ export class BaseAPI {
             // do not handle correctly sometimes.
             url += '?' + this.configuration.queryParamsStringify(context.query);
         }
-        const body = (context.body instanceof FormData || context.body instanceof URLSearchParams || isBlob(context.body))
+        const body = ((typeof FormData !== "undefined" && context.body instanceof FormData) || context.body instanceof URLSearchParams || isBlob(context.body))
 	    ? context.body
 	    : JSON.stringify(context.body);
 
diff --git a/samples/client/petstore/typescript-fetch/builds/default/runtime.ts b/samples/client/petstore/typescript-fetch/builds/default/runtime.ts
index 649e17504246..747ca17e206d 100644
--- a/samples/client/petstore/typescript-fetch/builds/default/runtime.ts
+++ b/samples/client/petstore/typescript-fetch/builds/default/runtime.ts
@@ -61,7 +61,7 @@ export class BaseAPI {
             // do not handle correctly sometimes.
             url += '?' + this.configuration.queryParamsStringify(context.query);
         }
-        const body = (context.body instanceof FormData || context.body instanceof URLSearchParams || isBlob(context.body))
+        const body = ((typeof FormData !== "undefined" && context.body instanceof FormData) || context.body instanceof URLSearchParams || isBlob(context.body))
 	    ? context.body
 	    : JSON.stringify(context.body);
 
diff --git a/samples/client/petstore/typescript-fetch/builds/es6-target/src/runtime.ts b/samples/client/petstore/typescript-fetch/builds/es6-target/src/runtime.ts
index 649e17504246..747ca17e206d 100644
--- a/samples/client/petstore/typescript-fetch/builds/es6-target/src/runtime.ts
+++ b/samples/client/petstore/typescript-fetch/builds/es6-target/src/runtime.ts
@@ -61,7 +61,7 @@ export class BaseAPI {
             // do not handle correctly sometimes.
             url += '?' + this.configuration.queryParamsStringify(context.query);
         }
-        const body = (context.body instanceof FormData || context.body instanceof URLSearchParams || isBlob(context.body))
+        const body = ((typeof FormData !== "undefined" && context.body instanceof FormData) || context.body instanceof URLSearchParams || isBlob(context.body))
 	    ? context.body
 	    : JSON.stringify(context.body);
 
diff --git a/samples/client/petstore/typescript-fetch/builds/multiple-parameters/runtime.ts b/samples/client/petstore/typescript-fetch/builds/multiple-parameters/runtime.ts
index 649e17504246..747ca17e206d 100644
--- a/samples/client/petstore/typescript-fetch/builds/multiple-parameters/runtime.ts
+++ b/samples/client/petstore/typescript-fetch/builds/multiple-parameters/runtime.ts
@@ -61,7 +61,7 @@ export class BaseAPI {
             // do not handle correctly sometimes.
             url += '?' + this.configuration.queryParamsStringify(context.query);
         }
-        const body = (context.body instanceof FormData || context.body instanceof URLSearchParams || isBlob(context.body))
+        const body = ((typeof FormData !== "undefined" && context.body instanceof FormData) || context.body instanceof URLSearchParams || isBlob(context.body))
 	    ? context.body
 	    : JSON.stringify(context.body);
 
diff --git a/samples/client/petstore/typescript-fetch/builds/prefix-parameter-interfaces/src/runtime.ts b/samples/client/petstore/typescript-fetch/builds/prefix-parameter-interfaces/src/runtime.ts
index 649e17504246..747ca17e206d 100644
--- a/samples/client/petstore/typescript-fetch/builds/prefix-parameter-interfaces/src/runtime.ts
+++ b/samples/client/petstore/typescript-fetch/builds/prefix-parameter-interfaces/src/runtime.ts
@@ -61,7 +61,7 @@ export class BaseAPI {
             // do not handle correctly sometimes.
             url += '?' + this.configuration.queryParamsStringify(context.query);
         }
-        const body = (context.body instanceof FormData || context.body instanceof URLSearchParams || isBlob(context.body))
+        const body = ((typeof FormData !== "undefined" && context.body instanceof FormData) || context.body instanceof URLSearchParams || isBlob(context.body))
 	    ? context.body
 	    : JSON.stringify(context.body);
 
diff --git a/samples/client/petstore/typescript-fetch/builds/typescript-three-plus/src/runtime.ts b/samples/client/petstore/typescript-fetch/builds/typescript-three-plus/src/runtime.ts
index b6e6a7744d78..8fae3715d1b6 100644
--- a/samples/client/petstore/typescript-fetch/builds/typescript-three-plus/src/runtime.ts
+++ b/samples/client/petstore/typescript-fetch/builds/typescript-three-plus/src/runtime.ts
@@ -61,7 +61,7 @@ export class BaseAPI {
             // do not handle correctly sometimes.
             url += '?' + this.configuration.queryParamsStringify(context.query);
         }
-        const body = (context.body instanceof FormData || context.body instanceof URLSearchParams || isBlob(context.body))
+        const body = ((typeof FormData !== "undefined" && context.body instanceof FormData) || context.body instanceof URLSearchParams || isBlob(context.body))
 	    ? context.body
 	    : JSON.stringify(context.body);
 
diff --git a/samples/client/petstore/typescript-fetch/builds/with-interfaces/runtime.ts b/samples/client/petstore/typescript-fetch/builds/with-interfaces/runtime.ts
index 649e17504246..747ca17e206d 100644
--- a/samples/client/petstore/typescript-fetch/builds/with-interfaces/runtime.ts
+++ b/samples/client/petstore/typescript-fetch/builds/with-interfaces/runtime.ts
@@ -61,7 +61,7 @@ export class BaseAPI {
             // do not handle correctly sometimes.
             url += '?' + this.configuration.queryParamsStringify(context.query);
         }
-        const body = (context.body instanceof FormData || context.body instanceof URLSearchParams || isBlob(context.body))
+        const body = ((typeof FormData !== "undefined" && context.body instanceof FormData) || context.body instanceof URLSearchParams || isBlob(context.body))
 	    ? context.body
 	    : JSON.stringify(context.body);
 
diff --git a/samples/client/petstore/typescript-fetch/builds/with-npm-version/src/runtime.ts b/samples/client/petstore/typescript-fetch/builds/with-npm-version/src/runtime.ts
index 649e17504246..747ca17e206d 100644
--- a/samples/client/petstore/typescript-fetch/builds/with-npm-version/src/runtime.ts
+++ b/samples/client/petstore/typescript-fetch/builds/with-npm-version/src/runtime.ts
@@ -61,7 +61,7 @@ export class BaseAPI {
             // do not handle correctly sometimes.
             url += '?' + this.configuration.queryParamsStringify(context.query);
         }
-        const body = (context.body instanceof FormData || context.body instanceof URLSearchParams || isBlob(context.body))
+        const body = ((typeof FormData !== "undefined" && context.body instanceof FormData) || context.body instanceof URLSearchParams || isBlob(context.body))
 	    ? context.body
 	    : JSON.stringify(context.body);