diff --git a/package-lock.json b/package-lock.json
index 0625226..e8c1fba 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -51,12 +51,14 @@
         "array-unique": {
           "version": "0.3.2",
           "resolved": "https://registry.npmjs.org/array-unique/-/array-unique-0.3.2.tgz",
-          "integrity": "sha1-qJS3XUvE9s1nnvMkSp/Y9Gri1Cg="
+          "integrity": "sha1-qJS3XUvE9s1nnvMkSp/Y9Gri1Cg=",
+          "optional": true
         },
         "braces": {
           "version": "2.3.2",
           "resolved": "https://registry.npmjs.org/braces/-/braces-2.3.2.tgz",
           "integrity": "sha512-aNdbnj9P8PjdXU4ybaWLK2IF3jc/EoDYbC7AazW6to3TRsfXxscC9UXOB5iDiEQrkyIbWp2SLQda4+QAa7nc3w==",
+          "optional": true,
           "requires": {
             "arr-flatten": "^1.1.0",
             "array-unique": "^0.3.2",
@@ -74,6 +76,7 @@
               "version": "2.0.1",
               "resolved": "https://registry.npmjs.org/extend-shallow/-/extend-shallow-2.0.1.tgz",
               "integrity": "sha1-Ua99YUrZqfYQ6huvu5idaxxWiQ8=",
+              "optional": true,
               "requires": {
                 "is-extendable": "^0.1.0"
               }
@@ -232,6 +235,7 @@
           "version": "4.0.0",
           "resolved": "https://registry.npmjs.org/fill-range/-/fill-range-4.0.0.tgz",
           "integrity": "sha1-1USBHUKPmOsGpj3EAtJAPDKMOPc=",
+          "optional": true,
           "requires": {
             "extend-shallow": "^2.0.1",
             "is-number": "^3.0.0",
@@ -243,6 +247,7 @@
               "version": "2.0.1",
               "resolved": "https://registry.npmjs.org/extend-shallow/-/extend-shallow-2.0.1.tgz",
               "integrity": "sha1-Ua99YUrZqfYQ6huvu5idaxxWiQ8=",
+              "optional": true,
               "requires": {
                 "is-extendable": "^0.1.0"
               }
@@ -302,7 +307,8 @@
         "is-extglob": {
           "version": "2.1.1",
           "resolved": "https://registry.npmjs.org/is-extglob/-/is-extglob-2.1.1.tgz",
-          "integrity": "sha1-qIwCU1eR8C7TfHahueqXc8gz+MI="
+          "integrity": "sha1-qIwCU1eR8C7TfHahueqXc8gz+MI=",
+          "optional": true
         },
         "is-glob": {
           "version": "4.0.0",
@@ -317,6 +323,7 @@
           "version": "3.0.0",
           "resolved": "https://registry.npmjs.org/is-number/-/is-number-3.0.0.tgz",
           "integrity": "sha1-JP1iAaR4LPUFYcgQJ2r8fRLXEZU=",
+          "optional": true,
           "requires": {
             "kind-of": "^3.0.2"
           },
@@ -325,6 +332,7 @@
               "version": "3.2.2",
               "resolved": "https://registry.npmjs.org/kind-of/-/kind-of-3.2.2.tgz",
               "integrity": "sha1-MeohpzS6ubuw8yRm2JOupR5KPGQ=",
+              "optional": true,
               "requires": {
                 "is-buffer": "^1.1.5"
               }
@@ -334,7 +342,8 @@
         "isobject": {
           "version": "3.0.1",
           "resolved": "https://registry.npmjs.org/isobject/-/isobject-3.0.1.tgz",
-          "integrity": "sha1-TkMekrEalzFjaqH5yNHMvP2reN8="
+          "integrity": "sha1-TkMekrEalzFjaqH5yNHMvP2reN8=",
+          "optional": true
         },
         "micromatch": {
           "version": "3.1.10",
@@ -3956,7 +3965,8 @@
         },
         "ansi-regex": {
           "version": "2.1.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -3974,11 +3984,13 @@
         },
         "balanced-match": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -3991,15 +4003,18 @@
         },
         "code-point-at": {
           "version": "1.1.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -4102,7 +4117,8 @@
         },
         "inherits": {
           "version": "2.0.3",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -4112,6 +4128,7 @@
         "is-fullwidth-code-point": {
           "version": "1.0.0",
           "bundled": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -4124,17 +4141,20 @@
         "minimatch": {
           "version": "3.0.4",
           "bundled": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
         },
         "minimist": {
           "version": "0.0.8",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.3.5",
           "bundled": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.2",
             "yallist": "^3.0.0"
@@ -4151,6 +4171,7 @@
         "mkdirp": {
           "version": "0.5.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -4223,7 +4244,8 @@
         },
         "number-is-nan": {
           "version": "1.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -4233,6 +4255,7 @@
         "once": {
           "version": "1.4.0",
           "bundled": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -4308,7 +4331,8 @@
         },
         "safe-buffer": {
           "version": "5.1.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -4338,6 +4362,7 @@
         "string-width": {
           "version": "1.0.2",
           "bundled": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -4355,6 +4380,7 @@
         "strip-ansi": {
           "version": "3.0.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -4393,11 +4419,13 @@
         },
         "wrappy": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.3",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         }
       }
     },
@@ -7674,7 +7702,8 @@
         "array-unique": {
           "version": "0.3.2",
           "resolved": "https://registry.npmjs.org/array-unique/-/array-unique-0.3.2.tgz",
-          "integrity": "sha1-qJS3XUvE9s1nnvMkSp/Y9Gri1Cg="
+          "integrity": "sha1-qJS3XUvE9s1nnvMkSp/Y9Gri1Cg=",
+          "optional": true
         },
         "braces": {
           "version": "2.3.2",
@@ -7914,7 +7943,8 @@
         "kind-of": {
           "version": "6.0.2",
           "resolved": "https://registry.npmjs.org/kind-of/-/kind-of-6.0.2.tgz",
-          "integrity": "sha512-s5kLOcnH0XqDO+FvuaLX8DDjZ18CGFk7VygH40QoKPUQhW4e2rvM0rwUq0t8IQDOwYSeLK01U90OjzBTme2QqA=="
+          "integrity": "sha512-s5kLOcnH0XqDO+FvuaLX8DDjZ18CGFk7VygH40QoKPUQhW4e2rvM0rwUq0t8IQDOwYSeLK01U90OjzBTme2QqA==",
+          "optional": true
         },
         "micromatch": {
           "version": "3.1.10",
@@ -9318,23 +9348,33 @@
       }
     },
     "terser": {
-      "version": "3.7.6",
-      "resolved": "https://registry.npmjs.org/terser/-/terser-3.7.6.tgz",
-      "integrity": "sha512-HbknfLRteizRcQWXTnpVK5rMleOEZh5g5y8sKzTm/W3pf4xrrdvajMSLMg2/45t0U8Hbk2+bcJ1IPXjO77kWtw==",
+      "version": "4.8.1",
+      "resolved": "https://registry.npmjs.org/terser/-/terser-4.8.1.tgz",
+      "integrity": "sha512-4GnLC0x667eJG0ewJTa6z/yXrbLGv80D9Ru6HIpCQmO+Q4PfEtBFi0ObSckqwL6VyQv/7ENJieXHo2ANmdQwgw==",
       "requires": {
-        "commander": "~2.14.1",
-        "source-map": "~0.6.1"
+        "commander": "^2.20.0",
+        "source-map": "~0.6.1",
+        "source-map-support": "~0.5.12"
       },
       "dependencies": {
         "commander": {
-          "version": "2.14.1",
-          "resolved": "https://registry.npmjs.org/commander/-/commander-2.14.1.tgz",
-          "integrity": "sha512-+YR16o3rK53SmWHU3rEM3tPAh2rwb1yPcQX5irVn7mb0gXbwuCCrnkbV5+PBfETdfg1vui07nM6PCG1zndcjQw=="
+          "version": "2.20.3",
+          "resolved": "https://registry.npmjs.org/commander/-/commander-2.20.3.tgz",
+          "integrity": "sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ=="
         },
         "source-map": {
           "version": "0.6.1",
           "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
           "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g=="
+        },
+        "source-map-support": {
+          "version": "0.5.21",
+          "resolved": "https://registry.npmjs.org/source-map-support/-/source-map-support-0.5.21.tgz",
+          "integrity": "sha512-uBHU3L3czsIyYXKX88fdrGovxdSCoTGDRZ6SYXtSRxLZUzHg5P/66Ht6uoUlHu9EZod+inXhKo3qQgwXUT/y1w==",
+          "requires": {
+            "buffer-from": "^1.0.0",
+            "source-map": "^0.6.0"
+          }
         }
       }
     },
diff --git a/package.json b/package.json
index 9033ba9..38fe0a6 100644
--- a/package.json
+++ b/package.json
@@ -58,7 +58,7 @@
     "shortid": "^2.2.8",
     "showdown": "^1.8.6",
     "sw-precache": "^5.2.1",
-    "terser": "^3.7.6",
+    "terser": "^4.8.1",
     "turndown": "^4.0.2",
     "uglifyify": "^5.0.0",
     "url-regex": "^4.1.1",