diff --git a/src/program.ts b/src/program.ts
index 64d758d..21710f2 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -38,6 +38,9 @@ function pickReturnType(argTypes: Type[], signatures: [Type[], Type][], stateTyp
 
 export class Program {
     constructor(private program: PluginProgram, private plugin: Plugin) {
+        this.runArguments = this.plugin.typeEnvironment.startTypes.map(
+            t => t[0].slice(1)
+        );
     };
 
     validate(): string[] {
diff --git a/test/test-interpreters.ts b/test/test-interpreters.ts
index 2bf451b..8d492b6 100644
--- a/test/test-interpreters.ts
+++ b/test/test-interpreters.ts
@@ -692,6 +692,8 @@ describe("various interpreters", () => {
             const prog = new Program(pluginProg, nfa);
             const stringType = nfa.typeEnvironment.getStringType();
 
+            assert.deepEqual([["string"]], prog.runArguments.map(t => t.map(t2 => t2.name)));
+
             let results;
             results = prog.run([new CoreValue(stringType, "11")]);
             assert.equal(3, results.states.length, "correct number of states");
diff --git a/test/test-plugin.ts b/test/test-plugin.ts
index 599555b..19c4ae3 100644
--- a/test/test-plugin.ts
+++ b/test/test-plugin.ts
@@ -50,6 +50,15 @@ describe("plugin", () => {
                 const pluginProgram = new context.global["plugin-stub"].Program({ elements: [] });
 
                 program = new Program(pluginProgram, plugin);
+
+                assert.deepEqual([
+                    ["any", "any"],
+                    ["number", "number"],
+                    ["number", "string"],
+                    ["string", "string"],
+                    ["string", "string"],
+                ], program.runArguments.map(t => t.map(t2 => t2.name)));
+
                 // const anyType = plugin.typeEnvironment.getType(plugin.typeEnvironment.checker.getAnyType());
                 stringType = plugin.typeEnvironment.getType(plugin.typeEnvironment.checker.getStringType());
                 numberType = plugin.typeEnvironment.getType(plugin.typeEnvironment.checker.getNumberType());
@@ -90,6 +99,8 @@ describe("plugin", () => {
                 const pluginProgram = new context.global["plugin-stub"].Program({ elements: [] });
 
                 program = new Program(pluginProgram, plugin);
+                assert.deepEqual([["any", "any"]], program.runArguments.map(t => t.map(t2 => t2.name)));
+
                 // const anyType = plugin.typeEnvironment.getType(plugin.typeEnvironment.checker.getAnyType());
                 stringType = plugin.typeEnvironment.getType(plugin.typeEnvironment.checker.getStringType());
                 numberType = plugin.typeEnvironment.getType(plugin.typeEnvironment.checker.getNumberType());