diff --git a/package/perl/perl.mk b/package/perl/perl.mk
index 0ff288db0e..a77686f951 100644
--- a/package/perl/perl.mk
+++ b/package/perl/perl.mk
@@ -79,7 +79,7 @@ endif
 define PERL_CONFIGURE_CMDS
 	(cd $(@D); $(TARGET_MAKE_ENV) HOSTCC='$(HOSTCC_NOCCACHE)' \
 		./configure $(PERL_CONF_OPTS))
-	$(SED) 's/UNKNOWN-/Buildroot $(BR2_VERSION_FULL) /' $(@D)/patchlevel.h
+	$(SED) 's/UNKNOWN-/Buildroot $(subst /,\/,$(BR2_VERSION_FULL)) /' $(@D)/patchlevel.h
 endef
 
 define PERL_BUILD_CMDS