diff --git a/src/main/scala/millfork/env/Environment.scala b/src/main/scala/millfork/env/Environment.scala
index a4e1acac..003d4987 100644
--- a/src/main/scala/millfork/env/Environment.scala
+++ b/src/main/scala/millfork/env/Environment.scala
@@ -684,6 +684,13 @@ class Environment(val parent: Option[Environment], val prefix: String, val cpuFa
             constantOperationForAsm(MathOperator.Exor, params)
           case "||" | "|" =>
             constantOperationForAsm(MathOperator.Or, params)
+          case "hi" =>
+            oneArgFunctionForAsm(_.hiByte, params)
+          case "lo" =>
+            oneArgFunctionForAsm(_.loByte, params)
+          case "nonet" | "sin" | "cos" | "tan" =>
+            log.error("Function not supported in inline assembly", e.position)
+            None
           case _ =>
             None
         }
@@ -699,6 +706,14 @@ class Environment(val parent: Option[Environment], val prefix: String, val cpuFa
     }
   }
 
+  private def oneArgFunctionForAsm(f: Constant => Constant, params: List[Expression]): Option[Constant] = {
+    if (params.size != 1) {
+      log.error("Too many arguments", params.headOption.flatMap(_.position))
+      return None
+    }
+    evalForAsm(params.head).map(f).map(_.quickSimplify)
+  }
+
   def registerAlias(stmt: AliasDefinitionStatement): Unit = {
     addThing(Alias(stmt.name, stmt.target), stmt.position)
   }
diff --git a/src/test/scala/millfork/test/AssemblySuite.scala b/src/test/scala/millfork/test/AssemblySuite.scala
index ee5d032d..375d7b0f 100644
--- a/src/test/scala/millfork/test/AssemblySuite.scala
+++ b/src/test/scala/millfork/test/AssemblySuite.scala
@@ -211,4 +211,18 @@ class AssemblySuite extends FunSuite with Matchers with AppendedClues {
     }
   }
 
+  test("Constants") {
+    EmuBenchmarkRun(
+      """
+        | const word COUNT = $400
+        | array a[COUNT]@$c000
+        | asm void main () {
+        |   LDA #hi(a.addr+COUNT)
+        |   RTS
+        | }
+      """.stripMargin){m =>
+
+    }
+  }
+
 }