diff --git a/lib/php/Makefile.am b/lib/php/Makefile.am
index e9d673c..da8ffdd 100755
--- a/lib/php/Makefile.am
+++ b/lib/php/Makefile.am
@@ -24,7 +24,7 @@
 
 if WITH_PHP_EXTENSION
 %.so:
-	cd src/ext/thrift_protocol/ && $(MAKE)
+    cd src/ext/thrift_protocol/ && $(MAKE)
 
 phpconfdir=$(PHP_CONFIG_PREFIX)
 phpconf_DATA=thrift_protocol.ini