diff --git a/scripts/pre-request.js b/scripts/pre-request.js
new file mode 100644
index 0000000..20e3bfc
--- /dev/null
+++ b/scripts/pre-request.js
@@ -0,0 +1,109 @@
+/*
+ * This is a Pre-request script for Postman client to remediate OAuth 1.0a issue
+ * where certain request fails if it has a query parameter that includes some special characters.
+ *
+ * NOTE: This Pre-script is only available for "GET" request.
+ *       Ther's a workaround for POST request.
+ *       See: https://github.com/twitterdev/postman-twitter-ads-api/issues/2
+ * 
+ * In order to use this Pre-request script, you need to change your "Authorization" type to
+ * "No Auth" only for the target request and do not apply to the top-level object.
+ */
+const oauth_consumer_key = pm.environment.get('consumer_key');
+const oauth_consumer_secret = pm.environment.get('consumer_secret');
+const oauth_token = pm.environment.get('access_token');
+const oauth_secret = pm.environment.get('token_secret');
+const oauth_signing_key = `${oauth_consumer_secret}&${oauth_secret}`;
+
+// create random oauth_nonce string
+const random_source = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
+var oauth_nonce = '';
+for (var i = 0; i < 32; i++) {
+    oauth_nonce += random_source.charAt(Math.floor(Math.random() * random_source.length));
+}
+
+const oauth_parameter_string_object = {};
+oauth_parameter_string_object.oauth_consumer_key = oauth_consumer_key;
+oauth_parameter_string_object.oauth_token = oauth_token;
+const oauth_nonce_array = CryptoJS.enc.Utf8.parse(oauth_nonce);
+oauth_parameter_string_object.oauth_nonce = encodeURIComponent(CryptoJS.enc.Base64.stringify(oauth_nonce_array));
+oauth_parameter_string_object.oauth_signature_method = 'HMAC-SHA1';
+oauth_parameter_string_object.oauth_version = '1.0';
+oauth_parameter_string_object.oauth_timestamp = Math.round((new Date()).getTime() / 1000);
+
+// for Authorization request header (copy object)
+const oauth_authorization_header_object = {};
+for (var key in oauth_parameter_string_object) {
+    oauth_authorization_header_object[key] = oauth_parameter_string_object[key];
+}
+
+// convert query string into object (+ encode)
+const url_query_string = pm.request.url.getQueryString({
+    ignoreDisabled: true
+});
+const url_query_string_array = url_query_string.split('&');
+let url_query_string_object = {};
+if (url_query_string !== "") {
+    url_query_string_object = JSON.parse(`{"${url_query_string.replace(/&/g, '","').replace(/=/g,'":"')}"}`, function(key, value) {return key === "" ? value : encodeURIComponent(value)});
+}
+
+// parse request.params
+for (var key in url_query_string_object) {
+    oauth_parameter_string_object[key] = url_query_string_object[key];
+}
+
+// sort object by key
+const oauth_parameter_string_object_ordered = {};
+Object.keys(oauth_parameter_string_object).sort().forEach(function(key) {
+    oauth_parameter_string_object_ordered[key] = oauth_parameter_string_object[key];
+});
+
+// convert object into array
+const oauth_parameter_string_array = [];
+for (var key in oauth_parameter_string_object_ordered) {
+    oauth_parameter_string_array.push(`${key}=${oauth_parameter_string_object_ordered[key]}`);
+}
+
+// generate parameter string
+const oauth_parameter_string = oauth_parameter_string_array.join('&');
+
+// replace dynamic variables
+let base_host = pm.request.url.getOAuth1BaseUrl();
+let regexp = /{{(.*?)}}/g;
+while (result = regexp.exec(base_host)) {
+    let value = pm.environment.get(result[1]);
+    base_host = base_host.replace(new RegExp(`{{${result[1]}}}`, 'g'), value);
+}
+
+// generate base string
+const oauth_base_string = `${pm.request.method}&${encodeURIComponent(base_host)}&${encodeURIComponent(oauth_parameter_string)}`;
+
+// generate signature
+const oauth_signature = CryptoJS.enc.Base64.stringify(CryptoJS.HmacSHA1(oauth_base_string, oauth_signing_key));
+
+oauth_authorization_header_object.oauth_signature = encodeURIComponent(oauth_signature);
+
+// convert object into array (for Authorization header string)
+const oauth_authorization_header_array = [];
+for (var key in oauth_authorization_header_object) {
+    oauth_authorization_header_array.push(`${key}="${oauth_authorization_header_object[key]}"`);
+}
+
+const oauth_authorization_header = oauth_authorization_header_array.join(', ');
+
+// generate Authorization header
+pm.request.headers.add({
+    key: 'Authorization',
+    value: 'OAuth ' + oauth_authorization_header
+});
+
+// Escape URI parameters using encodeURIComponent => RFC3986
+if (url_query_string_array.length !== 0) {
+    const request_parameter_array = [];
+    for (var key in url_query_string_object) {
+        request_parameter_array.push(key + '=' + url_query_string_object[key]);
+    }
+    const request_parameter_string = request_parameter_array.join('&');
+
+    pm.request.url = pm.request.url.getOAuth1BaseUrl() + "?" + request_parameter_string;
+}