diff --git a/configure.ac b/configure.ac
index ba24a322ee341c3763d8c0ec08ef405c78dbe3ce..53e1aeb81c23ea73becb234ddf6fd882475c5ccb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -50,7 +50,10 @@ AC_SUBST(BINARY_LDFLAGS)
 AC_SUBST(LIBDOVECOT_INCLUDE)
 
 AC_SUBST(PIGEONHOLE_ASSET_VERSION, regexp(AC_PACKAGE_VERSION, [^\([0-9]+\)\.\([0-9]+\).\([0-9]+\)], [\1.\2.\3]))
-AS_IF([test $PIGEONHOLE_ASSET_VERSION = "0.0.0"], [
+AS_IF([test "$PIGEONHOLE_ASSET_VERSION" = "0.0.0"], [
+  AC_SUBST([PIGEONHOLE_ASSET_VERSION], "main")
+])
+AS_IF([test "$PIGEONHOLE_ASSET_VERSION" = ""], [
    AC_SUBST([PIGEONHOLE_ASSET_VERSION], "main")
 ])