diff --git a/clr_loader/__init__.py b/clr_loader/__init__.py
index e5fca2a..2a141b2 100644
--- a/clr_loader/__init__.py
+++ b/clr_loader/__init__.py
@@ -139,7 +139,7 @@ def get_coreclr(
             candidates = [
                 rt for rt in find_runtimes() if rt.name == "Microsoft.NETCore.App"
             ]
-            candidates.sort(key=lambda spec: spec.version, reverse=True)
+            candidates.sort(key=lambda spec: spec.version_info, reverse=True)
             if not candidates:
                 raise RuntimeError("Failed to find a suitable runtime")
 
diff --git a/clr_loader/util/runtime_spec.py b/clr_loader/util/runtime_spec.py
index 89bf775..2e04c91 100644
--- a/clr_loader/util/runtime_spec.py
+++ b/clr_loader/util/runtime_spec.py
@@ -1,7 +1,7 @@
 import json
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Any, Dict, TextIO
+from typing import Any, Dict, TextIO, Tuple
 
 
 @dataclass
@@ -12,14 +12,19 @@ class DotnetCoreRuntimeSpec:
     version: str
     path: Path
 
+    @property
+    def version_info(self) -> Tuple[int, int, int, str]:
+        base, _, suffix = self.version.partition("-")
+        major, minor, patch = base.split(".")
+        return (int(major), int(minor), int(patch), suffix)
+
     @property
     def tfm(self) -> str:
-        return f"net{self.version[:3]}"
+        return f"net{self.version_info[0]}.{self.version_info[1]}"
 
     @property
     def floor_version(self) -> str:
-        major, minor, _ = self.version.split(".")
-        return f"{major}.{minor}.0"
+        return f"{self.version_info[0]}.{self.version_info[1]}.0"
 
     @property
     def runtime_config(self) -> Dict[str, Any]: