diff --git a/.gitattributes b/.gitattributes
index 069c6644..bfb843f0 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -2,4 +2,6 @@
 *.sln binary
 *.vcproj binary
 *.exe binary
-*.bin binary
+*.bin binary
+sim_rev.h export-subst
+
diff --git a/sim_rev.h b/sim_rev.h
index d0f3f87b..745280d9 100644
--- a/sim_rev.h
+++ b/sim_rev.h
@@ -48,6 +48,10 @@
 #include ".git-commit-id.h"
 #endif
 
+#if !defined(SIM_GIT_COMMIT_ID)
+#define SIM_GIT_COMMIT_ID $Format:%H$
+#endif
+
 /*
   The comment section below reflects the manual editing process which was in place
   prior to the use of the git source control system on at https://gihub.com/simh/simh