diff --git a/compiler/src/dotty/tools/dotc/core/TypeOps.scala b/compiler/src/dotty/tools/dotc/core/TypeOps.scala
index 8f87eddb6cef..c985ed23274b 100644
--- a/compiler/src/dotty/tools/dotc/core/TypeOps.scala
+++ b/compiler/src/dotty/tools/dotc/core/TypeOps.scala
@@ -284,7 +284,15 @@ object TypeOps:
           }
         case AndType(tp11, tp12) =>
           mergeRefinedOrApplied(tp11, tp2) & mergeRefinedOrApplied(tp12, tp2)
-        case tp1: TypeParamRef if tp1 == tp2 => tp1
+        case tp1: TypeParamRef =>
+          tp2.stripTypeVar match
+            case tp2: TypeParamRef if tp1 == tp2 => tp1
+            case _ => fail
+        case tp1: TypeVar =>
+          tp2 match
+            case tp2: TypeVar if tp1 == tp2 => tp1
+            case tp2: TypeParamRef if tp1.stripTypeVar == tp2 => tp2
+            case _ => fail
         case _ => fail
       }
     }
diff --git a/tests/pos/i23032.scala b/tests/pos/i23032.scala
new file mode 100644
index 000000000000..7e56d0f8b153
--- /dev/null
+++ b/tests/pos/i23032.scala
@@ -0,0 +1,2 @@
+def f[F[_], T, U]: F[T] | F[U] = ???
+def x = f.toString