diff --git a/rpm/pg-stat-monitor.spec b/rpm/pg-stat-monitor.spec
index 8be12cf..c9a2e58 100644
--- a/rpm/pg-stat-monitor.spec
+++ b/rpm/pg-stat-monitor.spec
@@ -33,7 +33,7 @@ It provides all the features of pg_stat_statment plus its own feature set.
 
 
 %build
-sed -i 's:PG_CONFIG = pg_config:PG_CONFIG = /usr/pgsql-%{pgrel}/bin/pg_config:' Makefile
+sed -i 's:PG_CONFIG ?= pg_config:PG_CONFIG = /usr/pgsql-%{pgrel}/bin/pg_config:' Makefile
 %{__make} USE_PGXS=1 %{?_smp_mflags}