diff --git a/rugnux/ResultReport.cpp b/rugnux/ResultReport.cpp
index 805150c30..8c3902113 100644
--- a/rugnux/ResultReport.cpp
+++ b/rugnux/ResultReport.cpp
@@ -442,8 +442,10 @@ ReportDocument BuildReportDocument(const std::string &output_prefix,
         // "-dirty" suffix marks uncommitted changes - and the compiler flags it was built with.
         // Both are provenance the version string does not carry: two builds of one commit can
         // differ by flags alone, and -march moves the CPU-bound results.
-        if (!jfjoch_git_sha1().empty())
-            Add(h, KeyText("RUGNUX_GIT", jfjoch_git_sha1() + " " + jfjoch_git_date()));
+        if (!jfjoch_git_sha1().empty()) {
+            const std::string git_date = jfjoch_git_date();
+            Add(h, KeyText("RUGNUX_GIT", git_date.empty() ? jfjoch_git_sha1() : jfjoch_git_sha1() + " " + git_date));
+        }
         Add(h, KeyText("BUILD_CXX_FLAGS",
                        jfjoch_build_cxx_flags().empty() ? "NONE" : jfjoch_build_cxx_flags()));
         Add(h, KeyText("DATE", time_UTC(std::chrono::system_clock::now())));