diff --git a/ext/pdo/Makefile.frag b/ext/pdo/Makefile.frag
index dc25c9f70b76c..8f08e9f654483 100644
--- a/ext/pdo/Makefile.frag
+++ b/ext/pdo/Makefile.frag
@@ -7,7 +7,12 @@ PDO_HEADER_FILES= \
 
 
 $(srcdir)/pdo_sql_parser.c: $(srcdir)/pdo_sql_parser.re
-	(cd $(top_srcdir); $(RE2C) --no-generation-date -o ext/pdo/pdo_sql_parser.c ext/pdo/pdo_sql_parser.re)
+	@(cd $(top_srcdir); \
+	if test -f ./pdo_sql_parser.re; then \
+		$(RE2C) --no-generation-date -o pdo_sql_parser.c pdo_sql_parser.re; \
+	else \
+		$(RE2C) --no-generation-date -o ext/pdo/pdo_sql_parser.c ext/pdo/pdo_sql_parser.re; \
+	fi)
 
 install-pdo-headers:
 	@echo "Installing PDO headers:          $(INSTALL_ROOT)$(phpincludedir)/ext/pdo/"