diff --git a/Makefile.generating b/Makefile.generating
index 174a2b7bd4944525c884101148b7d1bf947bdb41..58a6083f7db6c804da63afc6a845f00b1c25e652 100644
--- a/Makefile.generating
+++ b/Makefile.generating
@@ -41,8 +41,8 @@ tests/ptests_config: Makefile.generating share/Makefile.config
 	$(CHMOD_RO) $@
 
 ALL_LIBRARY_NAMES=$(shell ocamlfind query -r -p-format $(LIBRARY_NAMES) $(LIBRARY_NAMES_GUI))
-MAJOR_VERSION=$(shell $(SED) 's/^\([0-9]\+\)\..*/\1/' VERSION)
-MINOR_VERSION=$(shell $(SED) 's/^[0-9]\+\.\([0-9]\+\).*/\1/' VERSION)
+MAJOR_VERSION=$(shell $(SED) -E 's/^([0-9]+)\..*/\1/' VERSION)
+MINOR_VERSION=$(shell $(SED) -E 's/^[0-9]+\.([0-9]+).*/\1/' VERSION)
 
 $(CONFIG_FILE): $(CONFIG_FILE).in VERSION VERSION_CODENAME share/Makefile.config Makefile.generating configure.in
 	$(SED) \
@@ -211,7 +211,7 @@ endif
 
 lib/fc/META.frama-c: share/META.frama-c share/Makefile.config Makefile.generating
 	$(MKDIR) lib/fc/
-	$(SED) $< -e "s/@REQUIRES/$(LIBRARY_NAMES)/" > $@
+	$(SED) "s/@REQUIRES/$(LIBRARY_NAMES)/" $< > $@
 
 GENERATED += lib/fc/META.frama-c