diff --git a/rust2rpm/metadata.py b/rust2rpm/metadata.py
index b29e7b5..c0ce530 100644
--- a/rust2rpm/metadata.py
+++ b/rust2rpm/metadata.py
@@ -75,9 +75,9 @@ class CargoSemVer:
         version_str = f'{version.major}.{version.minor or 0}' \
             f'.{version.patch or 0}'
         if version.pre_release:
-            version_str = f'{version_str}{sep}{version.pre_release}'
+            version_str = f'{version_str}{sep}{version.pre_release.replace("-", "_")}'
         if version.build:
-            version_str = f'{version_str}+{version.build}'
+            version_str = f'{version_str}+{version.build.replace("-", "_")}'
         return version_str
 
     @staticmethod