diff --git a/project/Build.scala b/project/Build.scala
index b799c32eb65a..866808ab98ea 100644
--- a/project/Build.scala
+++ b/project/Build.scala
@@ -83,9 +83,9 @@ object DottyJSPlugin extends AutoPlugin {
 object Build {
   import ScaladocConfigs._
 
-  val referenceVersion = "3.3.1"
+  val referenceVersion = "3.4.0-RC1"
 
-  val baseVersion = "3.4.0-RC1"
+  val baseVersion = "3.4.1-RC1"
 
   // Versions used by the vscode extension to create a new project
   // This should be the latest published releases.
diff --git a/project/MiMaFilters.scala b/project/MiMaFilters.scala
index 8a1ea7d1141f..104d33683483 100644
--- a/project/MiMaFilters.scala
+++ b/project/MiMaFilters.scala
@@ -12,9 +12,66 @@ object MiMaFilters {
     ProblemFilters.exclude[ReversedMissingMethodProblem]("scala.quoted.Quotes#reflectModule#TypeReprMethods.dealiasKeepOpaques"),
     ProblemFilters.exclude[ReversedMissingMethodProblem]("scala.quoted.Quotes#reflectModule#SymbolMethods.paramVariance"),
     ProblemFilters.exclude[ReversedMissingMethodProblem]("scala.quoted.Quotes#reflectModule#TypeLambdaMethods.paramVariances"),
+    ProblemFilters.exclude[MissingClassProblem]("scala.annotation.internal.AssignedNonLocally"),
+    ProblemFilters.exclude[MissingClassProblem]("scala.annotation.internal.CaptureChecked"),
+    ProblemFilters.exclude[MissingClassProblem]("scala.annotation.internal.reachCapability"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.quoted.Quotes#reflectModule.ValOrDefDefTypeTest"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.quoted.Quotes#reflectModule.ValOrDefDefMethods"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.quoted.Quotes#reflectModule#SymbolMethods.paramVariance"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.quoted.Quotes#reflectModule#TypeLambdaMethods.paramVariances"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.quoted.Quotes#reflectModule#TypeReprMethods.dealiasKeepOpaques"),
+    ProblemFilters.exclude[MissingClassProblem]("scala.quoted.Quotes$reflectModule$ValOrDefDefMethods"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.quoted.Quotes#reflectModule#defnModule.FunctionClass"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.quoted.Quotes#reflectModule#defnModule.PolyFunctionClass"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.runtime.Tuples.reverse"),
+    ProblemFilters.exclude[MissingFieldProblem]("scala.runtime.stdLibPatches.language.3.4-migration"),
+    ProblemFilters.exclude[MissingFieldProblem]("scala.runtime.stdLibPatches.language.3.4"),
+    ProblemFilters.exclude[MissingFieldProblem]("scala.runtime.stdLibPatches.language.3.5-migration"),
+    ProblemFilters.exclude[MissingFieldProblem]("scala.runtime.stdLibPatches.language.3.5"),
+    ProblemFilters.exclude[MissingClassProblem]("scala.runtime.stdLibPatches.language$3$u002E4$"),
+    ProblemFilters.exclude[MissingClassProblem]("scala.runtime.stdLibPatches.language$3$u002E4$minusmigration$"),
+    ProblemFilters.exclude[MissingClassProblem]("scala.runtime.stdLibPatches.language$3$u002E5$"),
+    ProblemFilters.exclude[MissingClassProblem]("scala.runtime.stdLibPatches.language$3$u002E5$minusmigration$"),
+    ProblemFilters.exclude[MissingFieldProblem]("scala.runtime.stdLibPatches.language#deprecated.ascriptionVarargsUnpacking"),
+    ProblemFilters.exclude[MissingClassProblem]("scala.runtime.stdLibPatches.language$deprecated$ascriptionVarargsUnpacking$")
   )
   val TastyCore: Seq[ProblemFilter] = Seq(
     ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.EXPLICITtpt"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyBuffer.writeUtf8"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.AttributesSection"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.CAPTURECHECKEDattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.ELIDED"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.EXPLICITNULLSattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.JAVAattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.OUTLINEattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.SCALA2STANDARDLIBRARYattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.SOURCEFILEattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.WITHPUREFUNSattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.attributeTagToString"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.isBooleanAttrTag"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.isStringAttrTag"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.AttributesSection"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.ELIDED"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.isBooleanAttrTag"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.SCALA2STANDARDLIBRARYattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.EXPLICITNULLSattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.CAPTURECHECKEDattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.WITHPUREFUNSattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.JAVAattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.OUTLINEattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.isStringAttrTag"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.SOURCEFILEattr"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyFormat.attributeTagToString"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyHeaderUnpickler.this"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyHeaderUnpickler.this"),
+    ProblemFilters.exclude[MissingClassProblem]("dotty.tools.tasty.TastyHeaderUnpickler$Compatibility$"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("dotty.tools.tasty.TastyReader.readUtf8"),
+    ProblemFilters.exclude[MissingClassProblem]("dotty.tools.tasty.TastyVersion"),
+    ProblemFilters.exclude[MissingClassProblem]("dotty.tools.tasty.TastyVersion$"),
+    ProblemFilters.exclude[MissingClassProblem]("dotty.tools.tasty.UnpicklerConfig"),
+    ProblemFilters.exclude[MissingClassProblem]("dotty.tools.tasty.UnpicklerConfig$"),
+    ProblemFilters.exclude[MissingClassProblem]("dotty.tools.tasty.UnpicklerConfig$DefaultTastyVersion"),
+    ProblemFilters.exclude[MissingClassProblem]("dotty.tools.tasty.UnpicklerConfig$Generic")
   )
   val Interfaces: Seq[ProblemFilter] = Seq(
   )
diff --git a/sjs-compiler-tests/test/scala/dotty/tools/dotc/ScalaJSLink.scala b/sjs-compiler-tests/test/scala/dotty/tools/dotc/ScalaJSLink.scala
index 54e92b1559d6..2560021aec99 100644
--- a/sjs-compiler-tests/test/scala/dotty/tools/dotc/ScalaJSLink.scala
+++ b/sjs-compiler-tests/test/scala/dotty/tools/dotc/ScalaJSLink.scala
@@ -45,7 +45,7 @@ object ScalaJSLink:
     val result = PathIRContainer
       .fromClasspath(cpEntries.toSeq.map(entry => new File(entry).toPath()))
       .map(_._1)
-      .flatMap(cache.cached _)
+      .flatMap(cache.cached)
       .flatMap(linker.link(_, moduleInitializers, PathOutputDirectory(dir), logger))
 
     val report = Await.result(result, Duration.Inf)
diff --git a/tasty/src/dotty/tools/tasty/TastyFormat.scala b/tasty/src/dotty/tools/tasty/TastyFormat.scala
index ce3e1a852c74..765eb272d02a 100644
--- a/tasty/src/dotty/tools/tasty/TastyFormat.scala
+++ b/tasty/src/dotty/tools/tasty/TastyFormat.scala
@@ -318,7 +318,7 @@ object TastyFormat {
    *  compatibility, but remains backwards compatible, with all
    *  preceeding `MinorVersion`.
    */
-  final val MinorVersion: Int = 4
+  final val MinorVersion: Int = 5
 
   /** Natural Number. The `ExperimentalVersion` allows for
    *  experimentation with changes to TASTy without committing