diff --git a/schemas/WebpackOptions.json b/schemas/WebpackOptions.json
index e225c8b49..c874d21d5 100644
--- a/schemas/WebpackOptions.json
+++ b/schemas/WebpackOptions.json
@@ -122,7 +122,8 @@
         },
         {
           "description": "Every matched dependency becomes external.",
-          "instanceof": "RegExp"
+          "instanceof": "RegExp",
+          "tsType": "RegExp"
         }
       ]
     },
@@ -157,7 +158,8 @@
     "FilterItemTypes": {
       "anyOf": [
         {
-          "instanceof": "RegExp"
+          "instanceof": "RegExp",
+          "tsType": "RegExp"
         },
         {
           "type": "string"
@@ -238,7 +240,8 @@
               "type": "boolean"
             },
             {
-              "instanceof": "RegExp"
+              "instanceof": "RegExp",
+              "tsType": "RegExp"
             }
           ]
         },
@@ -253,12 +256,14 @@
               "type": "array",
               "items": {
                 "description": "A regular expression, when matched the module is not parsed",
-                "instanceof": "RegExp"
+                "instanceof": "RegExp",
+                "tsType": "RegExp"
               },
               "minItems": 1
             },
             {
-              "instanceof": "RegExp"
+              "instanceof": "RegExp",
+              "tsType": "RegExp"
             },
             {
               "instanceof": "Function",
@@ -310,7 +315,8 @@
               "type": "boolean"
             },
             {
-              "instanceof": "RegExp"
+              "instanceof": "RegExp",
+              "tsType": "RegExp"
             }
           ]
         },
@@ -340,7 +346,8 @@
         },
         "wrappedContextRegExp": {
           "description": "Set the inner regular expression for partial dynamic dependencies",
-          "instanceof": "RegExp"
+          "instanceof": "RegExp",
+          "tsType": "RegExp"
         }
       }
     },
@@ -554,7 +561,8 @@
                 "type": "string"
               },
               {
-                "instanceof": "RegExp"
+                "instanceof": "RegExp",
+                "tsType": "RegExp"
               },
               {
                 "type": "object",
@@ -642,13 +650,15 @@
                     "description": "Assign modules to a cache group by module name",
                     "oneOf": [
                       {
-                        "instanceof": "Function"
+                        "instanceof": "Function",
+                        "tsType": "Function"
                       },
                       {
                         "type": "string"
                       },
                       {
-                        "instanceof": "RegExp"
+                        "instanceof": "RegExp",
+                        "tsType": "RegExp"
                       }
                     ]
                   },
@@ -663,7 +673,8 @@
                         "type": "string"
                       },
                       {
-                        "instanceof": "RegExp"
+                        "instanceof": "RegExp",
+                        "tsType": "RegExp"
                       }
                     ]
                   }
@@ -1210,7 +1221,8 @@
     "RuleSetCondition": {
       "anyOf": [
         {
-          "instanceof": "RegExp"
+          "instanceof": "RegExp",
+          "tsType": "RegExp"
         },
         {
           "type": "string",
diff --git a/schemas/plugins/BannerPlugin.json b/schemas/plugins/BannerPlugin.json
index 555e29ed7..af313b90d 100644
--- a/schemas/plugins/BannerPlugin.json
+++ b/schemas/plugins/BannerPlugin.json
@@ -8,7 +8,8 @@
     "Rule": {
       "oneOf": [
         {
-          "instanceof": "RegExp"
+          "instanceof": "RegExp",
+          "tsType": "RegExp"
         },
         {
           "type": "string",
diff --git a/schemas/plugins/IgnorePlugin.json b/schemas/plugins/IgnorePlugin.json
index 924073868..83cd78ad8 100644
--- a/schemas/plugins/IgnorePlugin.json
+++ b/schemas/plugins/IgnorePlugin.json
@@ -7,11 +7,13 @@
       "properties": {
         "contextRegExp": {
           "description": "A RegExp to test the context (directory) against",
-          "instanceof": "RegExp"
+          "instanceof": "RegExp",
+          "tsType": "RegExp"
         },
         "resourceRegExp": {
           "description": "A RegExp to test the request against",
-          "instanceof": "RegExp"
+          "instanceof": "RegExp",
+          "tsType": "RegExp"
         }
       }
     },
diff --git a/schemas/plugins/SourceMapDevToolPlugin.json b/schemas/plugins/SourceMapDevToolPlugin.json
index 49ca38cf4..dd9d31090 100644
--- a/schemas/plugins/SourceMapDevToolPlugin.json
+++ b/schemas/plugins/SourceMapDevToolPlugin.json
@@ -3,7 +3,8 @@
     "rule": {
       "oneOf": [
         {
-          "instanceof": "RegExp"
+          "instanceof": "RegExp",
+          "tsType": "RegExp"
         },
         {
           "type": "string",
diff --git a/test/Schemas.lint.js b/test/Schemas.lint.js
index 66503cd00..30fc1b52f 100644
--- a/test/Schemas.lint.js
+++ b/test/Schemas.lint.js
@@ -76,7 +76,7 @@ describe("Schemas", () => {
 						}
 					});
 
-					if (Object.keys(item).indexOf("$ref") >= 0) {
+					if ("$ref" in item) {
 						it("should not have other properties next to $ref", () => {
 							const otherProperties = Object.keys(item).filter(
 								p => p !== "$ref"
@@ -91,6 +91,14 @@ describe("Schemas", () => {
 						});
 					}
 
+					if ("instanceof" in item) {
+						it("should have tsType specified when using instanceof", () => {
+							if (!("tsType" in item)) {
+								throw new Error("When using instanceof, tsType is required");
+							}
+						});
+					}
+
 					arrayProperties.forEach(prop => {
 						if (prop in item) {
 							describe(prop, () => {