diff --git a/Gruntfile.js b/Gruntfile.js
index ce390aebe8..c516673a68 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -47,11 +47,12 @@ module.exports = grunt => {
 
     let minifyLibFileList = copyJsFileList
         .filter(item => item.minify)
-        .reduce((map, item) => {
-            map[item.dest] = item.originalDest;
-
-            return map;
-        }, {});
+        .map(item => {
+            return {
+                dest: item.dest,
+                src: item.originalDest,
+            };
+        });
 
     let currentPath = path.dirname(fs.realpathSync(__filename));
 
diff --git a/application/Espo/Modules/Crm/Resources/metadata/app/jsLibs.json b/application/Espo/Modules/Crm/Resources/metadata/app/jsLibs.json
index d731819596..91225813c6 100644
--- a/application/Espo/Modules/Crm/Resources/metadata/app/jsLibs.json
+++ b/application/Espo/Modules/Crm/Resources/metadata/app/jsLibs.json
@@ -3,11 +3,13 @@
         "path": "client/modules/crm/lib/fullcalendar.js",
         "devPath": "client/modules/crm/lib/original/fullcalendar.js",
         "exportsTo": "$.fn",
-        "exportsAs": "fullCalendar"
+        "exportsAs": "fullCalendar",
+        "sourceMap": true
     },
     "vis": {
         "path": "client/modules/crm/lib/vis.js",
         "devPath": "client/modules/crm/lib/original/vis.js",
-        "exportsAs": "vis"
+        "exportsAs": "vis",
+        "sourceMap": true
     }
 }
diff --git a/application/Espo/Resources/metadata/app/jsLibs.json b/application/Espo/Resources/metadata/app/jsLibs.json
index 54320a84fc..6dc5473c7f 100644
--- a/application/Espo/Resources/metadata/app/jsLibs.json
+++ b/application/Espo/Resources/metadata/app/jsLibs.json
@@ -3,7 +3,8 @@
         "path": "client/lib/flotr2.js",
         "devPath": "client/lib/original/flotr2.js",
         "exportsTo": "window",
-        "exportsAs": "Flotr"
+        "exportsAs": "Flotr",
+        "sourceMap": true
     },
     "Base64": {
         "exportsTo": "window",
@@ -18,7 +19,8 @@
         "path": "client/lib/summernote.js",
         "devPath": "client/lib/original/summernote.js",
         "exportsTo": "$.fn",
-        "exportsAs": "summernote"
+        "exportsAs": "summernote",
+        "sourceMap": true
     },
     "Textcomplete": {
         "exportsTo": "$.fn",
@@ -34,12 +36,14 @@
         "path": "client/lib/cronstrue-i18n.js",
         "devPath": "client/lib/original/cronstrue-i18n.js",
         "exportsTo": "window",
-        "exportsAs": "cronstrue"
+        "exportsAs": "cronstrue",
+        "sourceMap": true
     },
     "Cropper": {
         "path": "client/lib/cropper.js",
         "exportsTo": "$.fn",
-        "exportsAs": "cropper"
+        "exportsAs": "cropper",
+        "sourceMap": true
     },
     "gridstack": {
         "exportsTo": "window",
@@ -54,13 +58,15 @@
         "path": "client/lib/exif.js",
         "devPath": "client/lib/original/exif.js",
         "exportsTo": "window",
-        "exportsAs": "EXIF"
+        "exportsAs": "EXIF",
+        "sourceMap": true
     },
     "JsBarcode": {
         "path": "client/lib/JsBarcode.all.js",
         "devPath": "client/lib/original/JsBarcode.all.js",
         "exportsTo": "window",
-        "exportsAs": "JsBarcode"
+        "exportsAs": "JsBarcode",
+        "sourceMap": true
     },
     "qrcode": {
         "path": "client/lib/qrcode.js",
diff --git a/client/src/loader.js b/client/src/loader.js
index e10809d6c8..3dddb5bcc9 100644
--- a/client/src/loader.js
+++ b/client/src/loader.js
@@ -65,6 +65,12 @@
         this._internalModuleMap = {};
 
         this.isDeveloperMode = false;
+
+        /**
+         * @type {string}
+         * @private
+         */
+        this._baseUrl = window.location.origin + window.location.pathname;
     };
 
     _.extend(Espo.Loader.prototype, /** @lends Espo.Loader.prototype */{
@@ -175,9 +181,21 @@
 
             if (!module && name.indexOf('lib!') === 0) {
                 noStrictMode = true;
+
+                if (!this.isDeveloperMode) {
+                    let readName = name.substring(4);
+
+                    let hasSourceMap = (this._libsConfig[readName] || {}).sourceMap
+
+                    if (hasSourceMap) {
+                        let realPath = path.split('?')[0];
+
+                        script += `\n//# sourceMappingURL=${this._baseUrl + realPath}.map`;
+                    }
+                }
             }
 
-            script += `\n//# sourceURL=/${path}`;
+            script += `\n//# sourceURL=${this._baseUrl + path}`;
 
             // For bc.
             if (module && module !== 'crm') {