diff --git a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
index 18294a28b4a1..e15e95392b67 100644
--- a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
+++ b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
@@ -4005,13 +4005,17 @@ object Parsers {
     def givenDef(start: Offset, mods: Modifiers, givenMod: Mod) = atSpan(start, nameStart) {
       var mods1 = addMod(mods, givenMod)
       val nameStart = in.offset
-      val name = if isIdent && followingIsGivenSig() then ident() else EmptyTermName
 
+      val givenSigPart =
+        if isIdent && followingIsGivenSig() then Some(ident())
+        else if followingIsGivenSig() then Some(EmptyTermName)
+        else None
+      val name = givenSigPart.getOrElse(EmptyTermName)
       val gdef =
         val tparams = typeParamClauseOpt(ParamOwner.Given)
         newLineOpt()
         val vparamss =
-          if in.token == LPAREN && in.lookahead.isIdent(nme.using)
+          if in.token == LPAREN && givenSigPart.nonEmpty
           then termParamClauses(ParamOwner.Given)
           else Nil
         newLinesOpt()
diff --git a/tests/neg/i19402.check b/tests/neg/i19402.check
new file mode 100644
index 000000000000..0792f82a627c
--- /dev/null
+++ b/tests/neg/i19402.check
@@ -0,0 +1,4 @@
+-- Error: tests/neg/i19402.scala:9:12 ----------------------------------------------------------------------------------
+9 |  given bar(foo: Foo): Bar = Bar(foo) // error
+  |            ^^^
+  |            `using` expected
diff --git a/tests/neg/i19402.scala b/tests/neg/i19402.scala
new file mode 100644
index 000000000000..112a70d9d188
--- /dev/null
+++ b/tests/neg/i19402.scala
@@ -0,0 +1,11 @@
+object Example {
+
+  class Bar(foo: Foo)
+  
+  class Foo
+  
+  given Foo = Foo()
+  
+  given bar(foo: Foo): Bar = Bar(foo) // error
+  
+}
diff --git a/tests/neg/i8150.check b/tests/neg/i8150.check
new file mode 100644
index 000000000000..373dc6a74355
--- /dev/null
+++ b/tests/neg/i8150.check
@@ -0,0 +1,16 @@
+-- Error: tests/neg/i8150.scala:3:16 -----------------------------------------------------------------------------------
+3 |type T = {given A with A} // error
+  |          ^^^^^^^^^^^^^^
+  |          refinement cannot be `given`
+-- [E040] Syntax Error: tests/neg/i8150.scala:4:23 ---------------------------------------------------------------------
+4 |type T = {given(using a: A) as B} // error // error
+  |                       ^
+  |                       an identifier expected, but ':' found
+-- [E040] Syntax Error: tests/neg/i8150.scala:4:28 ---------------------------------------------------------------------
+4 |type T = {given(using a: A) as B} // error // error
+  |                            ^^
+  |                            'with' expected, but identifier found
+-- [E040] Syntax Error: tests/neg/i8150.scala:5:8 ----------------------------------------------------------------------
+5 |// error
+  |        ^
+  |        '}' expected, but eof found
diff --git a/tests/neg/i8150.scala b/tests/neg/i8150.scala
index 2f0505c6265a..7266b359944e 100644
--- a/tests/neg/i8150.scala
+++ b/tests/neg/i8150.scala
@@ -1,3 +1,5 @@
 trait A
 trait B
-type T = {given(using a: A) as B} // error: refinement cannot be `given`
\ No newline at end of file
+type T = {given A with A} // error
+type T = {given(using a: A) as B} // error // error
+// error
\ No newline at end of file