diff --git a/part4/blog-fos/package-lock.json b/part4/blog-fos/package-lock.json
index 3f3a02d..f4cf7c9 100644
--- a/part4/blog-fos/package-lock.json
+++ b/part4/blog-fos/package-lock.json
@@ -1521,7 +1521,7 @@
     "buffer-equal-constant-time": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/buffer-equal-constant-time/-/buffer-equal-constant-time-1.0.1.tgz",
-      "integrity": "sha1-+OcRMvf/5uAaXJaXpMbz5I1cyBk="
+      "integrity": "sha512-zRpUiDwd/xk6ADqPMATG8vc9VPrkck7T07OIx0gnjmJAnHnTVXNQG3vfvWNuiZIkwu9KrKdA1iJKfsfTVxE6NA=="
     },
     "buffer-from": {
       "version": "1.1.2",
@@ -4267,26 +4267,23 @@
       }
     },
     "jsonwebtoken": {
-      "version": "8.5.1",
-      "resolved": "https://registry.npmjs.org/jsonwebtoken/-/jsonwebtoken-8.5.1.tgz",
-      "integrity": "sha512-XjwVfRS6jTMsqYs0EsuJ4LGxXV14zQybNd4L2r0UvbVnSF9Af8x7p5MzbJ90Ioz/9TI41/hTCvznF/loiSzn8w==",
+      "version": "9.0.0",
+      "resolved": "https://registry.npmjs.org/jsonwebtoken/-/jsonwebtoken-9.0.0.tgz",
+      "integrity": "sha512-tuGfYXxkQGDPnLJ7SibiQgVgeDgfbPq2k2ICcbgqW8WxWLBAxKQM/ZCu/IT8SOSwmaYl4dpTFCW5xZv7YbbWUw==",
       "requires": {
         "jws": "^3.2.2",
-        "lodash.includes": "^4.3.0",
-        "lodash.isboolean": "^3.0.3",
-        "lodash.isinteger": "^4.0.4",
-        "lodash.isnumber": "^3.0.3",
-        "lodash.isplainobject": "^4.0.6",
-        "lodash.isstring": "^4.0.1",
-        "lodash.once": "^4.0.0",
+        "lodash": "^4.17.21",
         "ms": "^2.1.1",
-        "semver": "^5.6.0"
+        "semver": "^7.3.8"
       },
       "dependencies": {
         "semver": {
-          "version": "5.7.1",
-          "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
-          "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ=="
+          "version": "7.3.8",
+          "resolved": "https://registry.npmjs.org/semver/-/semver-7.3.8.tgz",
+          "integrity": "sha512-NB1ctGL5rlHrPJtFDVIVzTyQylMLu9N9VICA6HSFJo8MCGVTMW6gfpicwKmmK/dAjTOrqu5l63JJOpDSrAis3A==",
+          "requires": {
+            "lru-cache": "^6.0.0"
+          }
         }
       }
     },
@@ -4378,8 +4375,7 @@
     "lodash": {
       "version": "4.17.21",
       "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
-      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==",
-      "dev": true
+      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg=="
     },
     "lodash.clonedeep": {
       "version": "4.5.0",
@@ -4397,47 +4393,12 @@
       "resolved": "https://registry.npmjs.org/lodash.get/-/lodash.get-4.4.2.tgz",
       "integrity": "sha1-LRd/ZS+jHpObRDjVNBSZ36OCXpk="
     },
-    "lodash.includes": {
-      "version": "4.3.0",
-      "resolved": "https://registry.npmjs.org/lodash.includes/-/lodash.includes-4.3.0.tgz",
-      "integrity": "sha1-YLuYqHy5I8aMoeUTJUgzFISfVT8="
-    },
-    "lodash.isboolean": {
-      "version": "3.0.3",
-      "resolved": "https://registry.npmjs.org/lodash.isboolean/-/lodash.isboolean-3.0.3.tgz",
-      "integrity": "sha1-bC4XHbKiV82WgC/UOwGyDV9YcPY="
-    },
-    "lodash.isinteger": {
-      "version": "4.0.4",
-      "resolved": "https://registry.npmjs.org/lodash.isinteger/-/lodash.isinteger-4.0.4.tgz",
-      "integrity": "sha1-YZwK89A/iwTDH1iChAt3sRzWg0M="
-    },
-    "lodash.isnumber": {
-      "version": "3.0.3",
-      "resolved": "https://registry.npmjs.org/lodash.isnumber/-/lodash.isnumber-3.0.3.tgz",
-      "integrity": "sha1-POdoEMWSjQM1IwGsKHMX8RwLH/w="
-    },
-    "lodash.isplainobject": {
-      "version": "4.0.6",
-      "resolved": "https://registry.npmjs.org/lodash.isplainobject/-/lodash.isplainobject-4.0.6.tgz",
-      "integrity": "sha1-fFJqUtibRcRcxpC4gWO+BJf1UMs="
-    },
-    "lodash.isstring": {
-      "version": "4.0.1",
-      "resolved": "https://registry.npmjs.org/lodash.isstring/-/lodash.isstring-4.0.1.tgz",
-      "integrity": "sha1-1SfftUVuynzJu5XV2ur4i6VKVFE="
-    },
     "lodash.merge": {
       "version": "4.6.2",
       "resolved": "https://registry.npmjs.org/lodash.merge/-/lodash.merge-4.6.2.tgz",
       "integrity": "sha512-0KpjqXRVvrYyCsX1swR/XTK0va6VQkQM6MNo7PqW77ByjAhoARA8EfrP1N4+KlKj8YS0ZUCtRT/YUuhyYDujIQ==",
       "dev": true
     },
-    "lodash.once": {
-      "version": "4.1.1",
-      "resolved": "https://registry.npmjs.org/lodash.once/-/lodash.once-4.1.1.tgz",
-      "integrity": "sha1-DdOXEhPHxW34gJd9UEyI+0cal6w="
-    },
     "lodash.truncate": {
       "version": "4.4.2",
       "resolved": "https://registry.npmjs.org/lodash.truncate/-/lodash.truncate-4.4.2.tgz",
diff --git a/part4/blog-fos/package.json b/part4/blog-fos/package.json
index 1a63d1d..5f99177 100644
--- a/part4/blog-fos/package.json
+++ b/part4/blog-fos/package.json
@@ -24,7 +24,7 @@
     "dotenv": "^8.2.0",
     "express": "^4.17.3",
     "express-async-errors": "^3.1.1",
-    "jsonwebtoken": "^8.5.1",
+    "jsonwebtoken": "^9.0.0",
     "mongoose": "^5.12.7",
     "mongoose-unique-validator": "^2.0.3"
   }
diff --git a/part4/blog-fos/yarn.lock b/part4/blog-fos/yarn.lock
index 106b1a0..6ce0e48 100644
--- a/part4/blog-fos/yarn.lock
+++ b/part4/blog-fos/yarn.lock
@@ -3226,21 +3226,15 @@ json5@^2.1.2:
   dependencies:
     minimist "^1.2.5"
 
-jsonwebtoken@^8.5.1:
-  version "8.5.1"
-  resolved "https://registry.yarnpkg.com/jsonwebtoken/-/jsonwebtoken-8.5.1.tgz#00e71e0b8df54c2121a1f26137df2280673bcc0d"
-  integrity sha512-XjwVfRS6jTMsqYs0EsuJ4LGxXV14zQybNd4L2r0UvbVnSF9Af8x7p5MzbJ90Ioz/9TI41/hTCvznF/loiSzn8w==
+jsonwebtoken@^9.0.0:
+  version "9.0.0"
+  resolved "https://registry.yarnpkg.com/jsonwebtoken/-/jsonwebtoken-9.0.0.tgz#d0faf9ba1cc3a56255fe49c0961a67e520c1926d"
+  integrity sha512-tuGfYXxkQGDPnLJ7SibiQgVgeDgfbPq2k2ICcbgqW8WxWLBAxKQM/ZCu/IT8SOSwmaYl4dpTFCW5xZv7YbbWUw==
   dependencies:
     jws "^3.2.2"
-    lodash.includes "^4.3.0"
-    lodash.isboolean "^3.0.3"
-    lodash.isinteger "^4.0.4"
-    lodash.isnumber "^3.0.3"
-    lodash.isplainobject "^4.0.6"
-    lodash.isstring "^4.0.1"
-    lodash.once "^4.0.0"
+    lodash "^4.17.21"
     ms "^2.1.1"
-    semver "^5.6.0"
+    semver "^7.3.8"
 
 jsprim@^1.2.2:
   version "1.4.1"
@@ -3370,41 +3364,6 @@ lodash.get@^4.0.2:
   resolved "https://registry.yarnpkg.com/lodash.get/-/lodash.get-4.4.2.tgz#2d177f652fa31e939b4438d5341499dfa3825e99"
   integrity sha1-LRd/ZS+jHpObRDjVNBSZ36OCXpk=
 
-lodash.includes@^4.3.0:
-  version "4.3.0"
-  resolved "https://registry.yarnpkg.com/lodash.includes/-/lodash.includes-4.3.0.tgz#60bb98a87cb923c68ca1e51325483314849f553f"
-  integrity sha1-YLuYqHy5I8aMoeUTJUgzFISfVT8=
-
-lodash.isboolean@^3.0.3:
-  version "3.0.3"
-  resolved "https://registry.yarnpkg.com/lodash.isboolean/-/lodash.isboolean-3.0.3.tgz#6c2e171db2a257cd96802fd43b01b20d5f5870f6"
-  integrity sha1-bC4XHbKiV82WgC/UOwGyDV9YcPY=
-
-lodash.isinteger@^4.0.4:
-  version "4.0.4"
-  resolved "https://registry.yarnpkg.com/lodash.isinteger/-/lodash.isinteger-4.0.4.tgz#619c0af3d03f8b04c31f5882840b77b11cd68343"
-  integrity sha1-YZwK89A/iwTDH1iChAt3sRzWg0M=
-
-lodash.isnumber@^3.0.3:
-  version "3.0.3"
-  resolved "https://registry.yarnpkg.com/lodash.isnumber/-/lodash.isnumber-3.0.3.tgz#3ce76810c5928d03352301ac287317f11c0b1ffc"
-  integrity sha1-POdoEMWSjQM1IwGsKHMX8RwLH/w=
-
-lodash.isplainobject@^4.0.6:
-  version "4.0.6"
-  resolved "https://registry.yarnpkg.com/lodash.isplainobject/-/lodash.isplainobject-4.0.6.tgz#7c526a52d89b45c45cc690b88163be0497f550cb"
-  integrity sha1-fFJqUtibRcRcxpC4gWO+BJf1UMs=
-
-lodash.isstring@^4.0.1:
-  version "4.0.1"
-  resolved "https://registry.yarnpkg.com/lodash.isstring/-/lodash.isstring-4.0.1.tgz#d527dfb5456eca7cc9bb95d5daeaf88ba54a5451"
-  integrity sha1-1SfftUVuynzJu5XV2ur4i6VKVFE=
-
-lodash.once@^4.0.0:
-  version "4.1.1"
-  resolved "https://registry.yarnpkg.com/lodash.once/-/lodash.once-4.1.1.tgz#0dd3971213c7c56df880977d504c88fb471a97ac"
-  integrity sha1-DdOXEhPHxW34gJd9UEyI+0cal6w=
-
 lodash.truncate@^4.4.2:
   version "4.4.2"
   resolved "https://registry.yarnpkg.com/lodash.truncate/-/lodash.truncate-4.4.2.tgz#5a350da0b1113b837ecfffd5812cbe58d6eae193"
@@ -4444,7 +4403,7 @@ semver-diff@^3.1.1:
   dependencies:
     semver "^6.3.0"
 
-"semver@2 || 3 || 4 || 5", semver@^5.5.0, semver@^5.6.0, semver@^5.7.1:
+"semver@2 || 3 || 4 || 5", semver@^5.5.0, semver@^5.7.1:
   version "5.7.1"
   resolved "https://registry.yarnpkg.com/semver/-/semver-5.7.1.tgz#a954f931aeba508d307bbf069eff0c01c96116f7"
   integrity sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ==
@@ -4454,10 +4413,10 @@ semver@^6.0.0, semver@^6.2.0, semver@^6.3.0:
   resolved "https://registry.yarnpkg.com/semver/-/semver-6.3.0.tgz#ee0a64c8af5e8ceea67687b133761e1becbd1d3d"
   integrity sha512-b39TBaTSfV6yBrapU89p5fKekE2m/NwnDocOVruQFS1/veMgdzuPcnOM34M6CwxW8jH/lxEa5rBoDeUwu5HHTw==
 
-semver@^7.2.1, semver@^7.3.2, semver@^7.3.4:
-  version "7.3.5"
-  resolved "https://registry.yarnpkg.com/semver/-/semver-7.3.5.tgz#0b621c879348d8998e4b0e4be94b3f12e6018ef7"
-  integrity sha512-PoeGJYh8HK4BTO/a9Tf6ZG3veo/A7ZVsYrSA6J8ny9nb3B1VrpkuN+z9OE5wfE5p6H4LchYZsegiQgbJD94ZFQ==
+semver@^7.2.1, semver@^7.3.2, semver@^7.3.4, semver@^7.3.8:
+  version "7.3.8"
+  resolved "https://registry.yarnpkg.com/semver/-/semver-7.3.8.tgz#07a78feafb3f7b32347d725e33de7e2a2df67798"
+  integrity sha512-NB1ctGL5rlHrPJtFDVIVzTyQylMLu9N9VICA6HSFJo8MCGVTMW6gfpicwKmmK/dAjTOrqu5l63JJOpDSrAis3A==
   dependencies:
     lru-cache "^6.0.0"