diff --git a/commands/spec.ts b/commands/spec.ts
index 9b83291..01bc59e 100644
--- a/commands/spec.ts
+++ b/commands/spec.ts
@@ -17,6 +17,38 @@ interface SPECOptions {
     benchmarks?: string[]
 
     buildType?: "nobuild" | "rebuild" | "plain",
+
+    /**
+     * Default: HTML and text
+     * Meaning: Desired report format.
+     * An output format may be deselected by prepending any of the names with the word "no".
+     * If more than one option is used, separate them by commas or colons.
+     * The values are not case-sensitive.
+     */
+    outputFormat?: ("all"
+        /** config file used for this run, written as a numbered file in the result directory, for example */
+        | "config"
+        /** Reportable syntax check */
+        | "check"
+        /**
+         * Comma-separated variable.
+         * If you populate spreadsheets from your runs,
+         * you probably should not cut/paste data from text files;
+         * you'll get more accurate data by using --output_format csv.
+         * The csv report includes all runs, more decimal places,
+         * system information, and even the compiler flags.
+         */
+        | "csv"
+        | "default"
+        | "flags"
+        | "html"
+        | "mail"
+        | "pdf"
+        | "postscript"
+        | "raw"
+        | "screen"
+        /** Plain ASCII text file */
+        | "text")[];
 }
 
 export function runcpuOptions(o: SPECOptions): string[] {
@@ -33,6 +65,7 @@ export function runcpuOptions(o: SPECOptions): string[] {
                     return []
             }
         }),
-        ...undefList(o.benchmarks, bench => bench)
+        ...undefList(o.benchmarks, bench => bench),
+        ...undefList(o.outputFormat, of => ["--output_format", of.join(",")]),
     ]
 }