diff --git a/Makefile b/Makefile
index a33319a..0a20b75 100644
--- a/Makefile
+++ b/Makefile
@@ -105,7 +105,8 @@ VERSION = $(shell [ -d .git ] && git describe HEAD | sed 's/mdadm-//')
 VERS_DATE = $(shell [ -d .git ] && date --iso-8601 --date="`git log -n1 --format=format:%cd --date=iso --date=short`")
 DVERS = $(if $(VERSION),-DVERSION=\"$(VERSION)\",)
 DDATE = $(if $(VERS_DATE),-DVERS_DATE="\"$(VERS_DATE)\"",)
-CFLAGS += $(DVERS) $(DDATE)
+DEXTRAVERSION = $(if $(EXTRAVERSION),-DEXTRAVERSION="\" - $(EXTRAVERSION)\"",)
+CFLAGS += $(DVERS) $(DDATE) $(DEXTRAVERSION)
 
 # The glibc TLS ABI requires applications that call clone(2) to set up
 # TLS data structures, use pthreads until mdmon implements this support
diff --git a/ReadMe.c b/ReadMe.c
index eaf1042..06b8f7e 100644
--- a/ReadMe.c
+++ b/ReadMe.c
@@ -33,7 +33,10 @@
 #ifndef VERS_DATE
 #define VERS_DATE "2018-10-01"
 #endif
-char Version[] = "mdadm - v" VERSION " - " VERS_DATE "\n";
+#ifndef EXTRAVERSION
+#define EXTRAVERSION ""
+#endif
+char Version[] = "mdadm - v" VERSION " - " VERS_DATE EXTRAVERSION "\n";
 
 /*
  * File: ReadMe.c