diff --git a/Package.swift b/Package.swift
index c6b13314..9887d7a2 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,8 +1,29 @@
-// swift-tools-version: 5.6
+// swift-tools-version: 5.4
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
 
+let czLibExcludes: [String] = [
+    "CMakeLists.txt", "ChangeLog", "FAQ", "INDEX",
+    "Makefile", "Makefile.in", "README",
+    "amiga/Makefile.pup", "amiga/Makefile.sas", "configure", "configure.log",
+    "doc/algorithm.txt", "doc/rfc1950.txt", "doc/rfc1951.txt",
+    "doc/rfc1952.txt", "doc/txtvsbin.txt", "make_vms.com",
+    "msdos/Makefile.bor", "msdos/Makefile.dj2",
+    "msdos/Makefile.emx", "msdos/Makefile.msc", "msdos/Makefile.tc",
+    "nintendods/Makefile", "nintendods/README",
+    "old/Makefile.emx", "old/Makefile.riscos", "old/README",
+    "old/descrip.mms", "old/os2/Makefile.os2", "old/visual-basic.txt",
+    "os400/README400", "os400/bndsrc", "os400/make.sh", "os400/zlib.inc",
+    "qnx/package.qpg", "treebuild.xml",
+    "watcom/watcom_f.mak", "watcom/watcom_l.mak",
+    "win32/DLL_FAQ.txt", "win32/Makefile.bor", "win32/Makefile.gcc",
+    "win32/Makefile.msc", "win32/README-WIN32.txt",
+    "win32/VisualC.txt", "win32/zlib1.rc",
+    "zconf.h.cmakein", "zconf.h.in", "zlib.3", "zlib.3.pdf",
+    "zlib.map", "zlib.pc", "zlib.pc.cmakein", "zlib.pc.in", "zlib2ansi"
+]
+
 #if os(Linux)
 let osdep: [Target.Dependency] = ["LinuxBridge"]
 let ostag: [Target] = [.target(name: "LinuxBridge"), .target(name: "PerfectCSQLite3")]
@@ -34,7 +55,7 @@ let package = Package(
         .target(name: "COpenSSL"),
         .target(name: "cURL"),
         .target(name: "PerfectAuth", dependencies: ["PerfectCrypto"]),
-        .target(name: "PerfectCZlib"),
+        .target(name: "PerfectCZlib", exclude: czLibExcludes),
         .target(name: "PerfectCHTTPParser"),
         .target(name: "PerfectLib", dependencies: osdep),
         .target(name: "PerfectThread", dependencies: osdep),
diff --git a/Sources/PerfectCRUD/Coding/CodingNames.swift b/Sources/PerfectCRUD/Coding/CodingNames.swift
index 89e9c382..144d0206 100644
--- a/Sources/PerfectCRUD/Coding/CodingNames.swift
+++ b/Sources/PerfectCRUD/Coding/CodingNames.swift
@@ -331,8 +331,8 @@ struct SubTable<T: Decodable, R: Decodable>: SubTableProto {
 }
 
 extension Decodable where Self: Encodable {
-	// !FIX! causing ciompiler crash
-	func makeSubTable(name: String, decoder: CRUDColumnNameDecoder) -> some SubTableProto {
+    @available(macOS 10.15.0, *)
+    func makeSubTable(name: String, decoder: CRUDColumnNameDecoder) -> some SubTableProto {
 		return SubTable(name: name, type: Self.self, decoder: decoder, realType: Self.self)
 	}