diff --git a/core/build.gradle.kts b/core/build.gradle.kts
index fd373baae..d45404450 100644
--- a/core/build.gradle.kts
+++ b/core/build.gradle.kts
@@ -97,7 +97,7 @@ configure<BlossomExtension> {
 }
 
 fun Project.buildNumber(): Int =
-    System.getenv("BUILD_NUMBER")?.let { Integer.parseInt(it) } ?: -1
+    (System.getenv("GITHUB_RUN_NUMBER") ?: jenkinsBuildNumber())?.let { Integer.parseInt(it) } ?: -1
 
 inner class GitInfo {
     val branch: String
@@ -129,3 +129,6 @@ inner class GitInfo {
         repository = git?.repository?.config?.getString("remote", "origin", "url") ?: ""
     }
 }
+
+// todo remove this when we're not using Jenkins anymore
+private fun jenkinsBuildNumber(): String? = System.getenv("BUILD_NUMBER")