diff --git a/parm/config/gfs/config.base b/parm/config/gfs/config.base
index 64f39c9f04..d24f1ad3c3 100644
--- a/parm/config/gfs/config.base
+++ b/parm/config/gfs/config.base
@@ -95,7 +95,7 @@ export MODE="@MODE@" # cycled/forecast-only
 # Build paths relative to $HOMEgfs
 export FIXgsi="${HOMEgfs}/fix/gsi"
 export HOMEpost="${HOMEgfs}"
-export HOMEobsproc="${BASE_GIT:-}/obsproc/v${obsproc_run_ver}"
+export HOMEobsproc="${BASE_GIT:-}/obsproc/v${obsproc_run_ver:-}"
 
 # CONVENIENT utility scripts and other environment parameters
 export NCP="/bin/cp -p"