diff --git a/package.json b/package.json
index bde6df2..5e46f5e 100644
--- a/package.json
+++ b/package.json
@@ -154,22 +154,32 @@
                     "default": true,
                     "description": "When snippet is enabled, hide the snippets' corresponding commands from completion items."
                 },
-                "texinfo.preview.customCSS": {
-                    "type": "string",
-                    "default": "",
-                    "description": "URI of custom CSS for preview."
-                },
                 "texinfo.enableCodeLens": {
                     "type": "boolean",
                     "default": true,
                     "description": "Enable code lens on node identifiers which jumps to the corresponding nodes in preview."
                 },
+                "texinfo.makeinfo": {
+                    "type": "string",
+                    "default": "makeinfo",
+                    "description": "Path to the makeinfo (or texi2any) command."
+                },
+                "texinfo.preview.customCSS": {
+                    "type": "string",
+                    "default": "",
+                    "description": "URI of custom CSS for preview."
+                },
                 "texinfo.preview.errorLimit": {
                     "type": "integer",
                     "default": 100,
                     "minimum": 0,
                     "description": "Max number of errors before quit when trying to display preview."
                 },
+                "texinfo.preview.includePaths": {
+                    "type": "array",
+                    "default": [],
+                    "description": "Extra paths to search for @include files."
+                },
                 "texinfo.preview.maxSize": {
                     "type": "integer",
                     "default": 2,
@@ -177,11 +187,6 @@
                     "maximum": 16,
                     "description": "Max allowed size (in MiB) for the preview document."
                 },
-                "texinfo.makeinfo": {
-                    "type": "string",
-                    "default": "makeinfo",
-                    "description": "Path to the `makeinfo` (or `texi2any`) command."
-                },
                 "texinfo.preview.noHeaders": {
                     "type": "boolean",
                     "default": false,
@@ -197,10 +202,10 @@
                     "default": false,
                     "description": "Suppress warnings."
                 },
-                "texinfo.vars": {
+                "texinfo.preview.variables": {
                     "type": "array",
                     "default": [],
-                    "description": "Define variables."
+                    "description": "Define variables (as with @set)."
                 }
             }
         },
diff --git a/src/options.ts b/src/options.ts
index cf46d68..36e83ab 100644
--- a/src/options.ts
+++ b/src/options.ts
@@ -52,6 +52,10 @@ export default class Options {
         return this.getNumber('preview.errorLimit');
     }
 
+    get includePaths() {
+        return this.getArray('preview.includePaths');
+    }
+
     get maxSize() {
         return this.getNumber('preview.maxSize') * 1024 * 1024;
     }
@@ -68,14 +72,14 @@ export default class Options {
         return this.getBoolean('preview.noWarnings');
     }
 
-    get vars() {
-        return this.getArray('vars');
+    get variables() {
+        return this.getArray('preview.variables');
     }
 
     private readonly configuration = vscode.workspace.getConfiguration('texinfo');
 
-    private getArray(section: string) {
-        return this.configuration.get(section, <readonly string[]>[]);
+    private getArray(section: string): readonly string[] {
+        return this.configuration.get(section, []);
     }
 
     private getBoolean(section: string) {
diff --git a/src/utils/converter.ts b/src/utils/converter.ts
index cba6d19..1930fdc 100644
--- a/src/utils/converter.ts
+++ b/src/utils/converter.ts
@@ -19,7 +19,7 @@
  * vscode-texinfo.  If not, see <https://www.gnu.org/licenses/>.
  */
 
- import * as path from 'path';
+import * as path from 'path';
 import * as vscode from 'vscode';
 import Logger from '../logger';
 import Options from '../options';
@@ -41,8 +41,9 @@ export default class Converter {
         if (insertScript !== undefined) {
             options.push('--set-customization-variable', `EXTRA_HEAD <script>${insertScript}</script>`);
         }
+        this.addIncludePaths(this.options.includePaths, options);
+        this.defineVariables(this.options.variables, options);
         this.includeCustomCSS(this.options.customCSS, options);
-        this.addVars(this.options.vars, options);
         return await exec(this.options.makeinfo, options.concat(this.path), this.options.maxSize);
     }
 
@@ -53,8 +54,13 @@ export default class Converter {
         private readonly logger: Logger,
     ) {}
 
-    private addVars(vars: readonly string[], options: string[]) {
-        vars.forEach(varName => options.push('-D', varName));
+    private addIncludePaths(paths: readonly string[], options: string[]) {
+        const separator = process.platform === 'win32' ? ';' : ':';
+        options.push('-I', paths.join(separator));
+    }
+
+    private defineVariables(variables: readonly string[], options: string[]) {
+        variables.forEach(varName => options.push('-D', varName));
     }
 
     private includeCustomCSS(cssFileURI: string, options: string[]) {