3 files changed, 76 insertions, 3 deletions
diff --git a/src/dotty/tools/dotc/typer/ProtoTypes.scala b/src/dotty/tools/dotc/typer/ProtoTypes.scala
index 0e6697fb7..751ed928b 100644
--- a/src/dotty/tools/dotc/typer/ProtoTypes.scala
+++ b/src/dotty/tools/dotc/typer/ProtoTypes.scala
@@ -395,9 +395,10 @@ object ProtoTypes {
           if (mt.isDependent) tp
           else {
             val rt = normalize(mt.resultType, pt)
-            if (pt.isInstanceOf[ApplyingProto])
-              mt.derivedMethodType(mt.paramNames, mt.paramTypes, rt)
-            else {
+          pt match {
+            case pt: IgnoredProto  => mt
+            case pt: ApplyingProto => mt.derivedMethodType(mt.paramNames, mt.paramTypes, rt)
+            case _ =>
               val ft = defn.FunctionOf(mt.paramTypes, rt)
               if (mt.paramTypes.nonEmpty || ft <:< pt) ft else rt
             }
diff --git a/tests/run/i1543.check b/tests/run/i1543.check
new file mode 100644
index 000000000..10adcaf83
--- /dev/null
+++ b/tests/run/i1543.check
@@ -0,0 +1,31 @@
+1
+2
+3
+4
+5
+6
+7
+8
+9
+10
+11
+12
+13
+14
+15
+16
+17
+18
+19
+20
+21
+22
+23
+24
+25
+26
+27
+28
+29
+30
+31
diff --git a/tests/run/i1543.scala b/tests/run/i1543.scala
new file mode 100644
index 000000000..268bc717b
--- /dev/null
+++ b/tests/run/i1543.scala
@@ -0,0 +1,41 @@
+
+object Test extends dotty.runtime.LegacyApp {
+  new Bar().foo(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
+}
+
+
+class Bar {
+  def foo(p1: Int, p2: Int, p3: Int, p4: Int, p5: Int, p6: Int, p7: Int, p8: Int, p9: Int, p10: Int, p11: Int, p12: Int, p13: Int, p14: Int, p15: Int, p16: Int, p17: Int, p18: Int, p19: Int, p20: Int, p21: Int, p22: Int, p23: Int, p24: Int, p25: Int, p26: Int, p27: Int, p28: Int, p29: Int, p30: Int, p31: Int): Unit = {
+    println(p1)
+    println(p2)
+    println(p3)
+    println(p4)
+    println(p5)
+    println(p6)
+    println(p7)
+    println(p8)
+    println(p9)
+    println(p10)
+    println(p11)
+    println(p12)
+    println(p13)
+    println(p14)
+    println(p15)
+    println(p16)
+    println(p17)
+    println(p18)
+    println(p19)
+    println(p20)
+    println(p21)
+    println(p22)
+    println(p23)
+    println(p24)
+    println(p25)
+    println(p26)
+    println(p27)
+    println(p28)
+    println(p29)
+    println(p30)
+    println(p31)
+  }
+}