diff --git a/src/main/kotlin/no/uio/microobject/runtime/Interpreter.kt b/src/main/kotlin/no/uio/microobject/runtime/Interpreter.kt
index cab032d..02c1949 100644
--- a/src/main/kotlin/no/uio/microobject/runtime/Interpreter.kt
+++ b/src/main/kotlin/no/uio/microobject/runtime/Interpreter.kt
@@ -68,10 +68,21 @@ class Interpreter(
     // TripleManager used to provide virtual triples etc.
     val tripleManager : TripleManager = TripleManager(settings, staticInfo, this)
 
-    //evaluates a call on cl.nm on thisVar
-    //Must ONLY be called if nm is checked to have no side-effects (i.e., is rule)
-    //First return value is the created object, the second the return value
-    fun evalCall(objName: String, className: String, metName: String): Pair<LiteralExpr, LiteralExpr> {
+    /**
+     * Evaluates a call on a method of a class
+     *
+     * This method is used to evaluate a call on a method of a class. It constructs the initial state, adds the
+     * parameters to the memory, and runs the interpreter until the return value is reached.
+     * Must ONLY be called if nm is checked to have no side-effects (i.e., is rule)
+     *
+     * @param objName the name of the object
+     * @param className the name of the class
+     * @param metName the name of the method
+     * @param params the parameters of the method. It must be structured as "paramName" to "paramValue" as a LiteralExpr as a map
+     * @return a pair of the created object and the return value
+     * @throws Exception if an error occurs during the generation of the builtin
+     */
+    fun evalCall(objName: String, className: String, metName: String, params: Map<String, LiteralExpr> = mapOf()): Pair<LiteralExpr, LiteralExpr> {
         //Construct initial state
         val classStmt =
             staticInfo.methodTable[className]
@@ -84,6 +95,14 @@ class Interpreter(
             heap.keys.first { it.literal == objName }.tag //retrieve real class, because rule methods can be inheritated
         )
         mem["this"] = obj
+
+        // Add parameters to memory
+        if (params.isNotEmpty()) {
+            for ((paramName, paramExpr) in params) {
+                mem[paramName] = paramExpr
+            }
+        }
+
         val myId = Names.getStackId()
         val se = StackEntry(met.stmt, mem, obj, myId)
         stack.push(se)
diff --git a/src/test/kotlin/no/uio/microobject/test/runtime/Interpreter.kt b/src/test/kotlin/no/uio/microobject/test/runtime/Interpreter.kt
index 77a0b36..eade7e3 100644
--- a/src/test/kotlin/no/uio/microobject/test/runtime/Interpreter.kt
+++ b/src/test/kotlin/no/uio/microobject/test/runtime/Interpreter.kt
@@ -4,6 +4,8 @@ import io.kotest.matchers.shouldBe
 import no.uio.microobject.ast.expr.LiteralExpr
 import no.uio.microobject.test.MicroObjectTest
 import no.uio.microobject.type.*
+import org.apache.jena.rdf.model.impl.LiteralImpl
+import kotlin.test.assertEquals
 
 class Interpreter : MicroObjectTest() {
     private fun evalTest() {
@@ -24,10 +26,23 @@ class Interpreter : MicroObjectTest() {
         person.size shouldBe 2
     }
 
+    private fun evalParamsTest() {
+        val (interpreter, _) = initInterpreter("eval-params", StringLoad.RES)
+        executeUntilBreak(interpreter)
+
+        interpreter.evalCall(interpreter.getObjectNames("A")[0].toString(), "A", "setX", mapOf("newX" to LiteralExpr("1", INTTYPE)))
+        val queryRes = interpreter.query("SELECT * WHERE { ?obj a prog:A . ?obj prog:A_x ?x }")
+        queryRes!!.hasNext() shouldBe true
+
+        val x = queryRes.next()
+        assertEquals(1, (x["x"] as LiteralImpl).int)
+    }
+
     init {
         "eval" {
             evalTest()
             getObjectNamesTest()
+            evalParamsTest()
         }
     }
 }
\ No newline at end of file
diff --git a/src/test/resources/eval-params.smol b/src/test/resources/eval-params.smol
new file mode 100644
index 0000000..0f88cf1
--- /dev/null
+++ b/src/test/resources/eval-params.smol
@@ -0,0 +1,10 @@
+class A(Int x)
+    Unit setX(Int newX)
+        this.x = newX;
+    end
+end
+
+main
+    A a = new A(5);
+    breakpoint;
+end
\ No newline at end of file