diff --git a/compiler/semtypes.nim b/compiler/semtypes.nim
index 1219d6ed83..a5cd5b5b02 100644
--- a/compiler/semtypes.nim
+++ b/compiler/semtypes.nim
@@ -1646,7 +1646,8 @@ proc semGeneric(c: PContext, n: PNode, s: PSym, prev: PType): PType =
     recomputeFieldPositions(tx, tx.n, position)
 
 proc maybeAliasType(c: PContext; typeExpr, prev: PType): PType =
-  if typeExpr.kind in {tyObject, tyEnum, tyDistinct, tyForward, tyGenericBody} and prev != nil:
+  if prev != nil and (prev.kind == tyGenericBody or
+      typeExpr.kind in {tyObject, tyEnum, tyDistinct, tyForward, tyGenericBody}):
     result = newTypeS(tyAlias, c)
     result.rawAddSon typeExpr
     result.sym = prev.sym
diff --git a/tests/generics/taliashijack.nim b/tests/generics/taliashijack.nim
new file mode 100644
index 0000000000..fdebadded2
--- /dev/null
+++ b/tests/generics/taliashijack.nim
@@ -0,0 +1,8 @@
+# issue #23977
+
+type Foo[T] = int
+
+proc foo(T: typedesc) =
+  var a: T
+
+foo(int)
diff --git a/tests/vm/tvmmisc.nim b/tests/vm/tvmmisc.nim
index d28f765740..3c4b47c48d 100644
--- a/tests/vm/tvmmisc.nim
+++ b/tests/vm/tvmmisc.nim
@@ -566,7 +566,7 @@ block:
 block:
   static:
     let x = int 1
-    doAssert $(x.type) == "Foo"  # Foo
+    doAssert $(x.type) == "int"  # Foo
 
 block:
   static: