diff --git a/Makefile b/Makefile
index 97e933694..c085872a1 100644
--- a/Makefile
+++ b/Makefile
@@ -1,101 +1,101 @@
 TMPL_DIR := templates-cfg
 OP_TMPL_DIR := templates-op
 BUILD_DIR := build
 CFLAGS :=
 
 src = $(wildcard interface-definitions/*.xml.in)
 obj = $(src:.xml.in=.xml)
 
 %.xml: %.xml.in
 	@echo Generating $(BUILD_DIR)/$@ from $<
 	# -ansi      This turns off certain features of GCC that are incompatible
 	#            with ISO C90. Without this regexes containing '/' as in an URL
 	#            won't work
 	# -x c       By default GCC guesses the input language from its file extension,
 	#            thus XML is unknown. Force it to C language
 	# -E         Stop after the preprocessing stage
 	# -undef     Do not predefine any system-specific or GCC-specific macros.
 	# -nostdinc  Do not search the standard system directories for header files
 	# -P         Inhibit generation of linemarkers in the output from the
 	#            preprocessor
-	@$(CC) -ansi -x c -E -undef -nostdinc -P -I$(CURDIR)/interface-definitions -o $(BUILD_DIR)/$@ -c $<
+	@$(CC) -x c-header -E -undef -nostdinc -P -I$(CURDIR)/interface-definitions -o $(BUILD_DIR)/$@ -c $<
 
 $(BUILD_DIR):
 	install -d -m 0755 $(BUILD_DIR)/interface-definitions
 	install -d -m 0755 $(BUILD_DIR)/op-mode-definitions
 
 .PHONY: interface_definitions
 .ONESHELL:
 interface_definitions: $(BUILD_DIR) $(obj)
 	mkdir -p $(TMPL_DIR)
 
 	find $(BUILD_DIR)/interface-definitions -type f -name "*.xml" | xargs -I {} $(CURDIR)/scripts/build-command-templates {} $(CURDIR)/schema/interface_definition.rng $(TMPL_DIR) || exit 1
 
 	# XXX: delete top level node.def's that now live in other packages
 	rm -f $(TMPL_DIR)/firewall/node.def
 	rm -f $(TMPL_DIR)/interfaces/node.def
 	rm -f $(TMPL_DIR)/interfaces/bonding/node.tag/ip/node.def
 	rm -f $(TMPL_DIR)/interfaces/bonding/node.tag/vif/node.tag/ip/node.def
 	rm -f $(TMPL_DIR)/interfaces/bridge/node.tag/ip/node.def
 	rm -f $(TMPL_DIR)/interfaces/ethernet/node.tag/ip/node.def
 	rm -f $(TMPL_DIR)/interfaces/ethernet/node.tag/vif/node.tag/ip/node.def
 	rm -f $(TMPL_DIR)/interfaces/ethernet/node.tag/vif-s/node.tag/ip/node.def
 	rm -f $(TMPL_DIR)/interfaces/ethernet/node.tag/vif-s/node.tag/vif-c/node.tag/ip/node.def
 	rm -f $(TMPL_DIR)/interfaces/vxlan/node.tag/ip/node.def
 	rm -f $(TMPL_DIR)/interfaces/wireless/node.tag/vif/node.tag/ip/node.def
 	rm -f $(TMPL_DIR)/protocols/node.def
 	rm -f $(TMPL_DIR)/protocols/static/node.def
 	rm -f $(TMPL_DIR)/system/node.def
 	rm -f $(TMPL_DIR)/system/options/node.def
 	rm -f $(TMPL_DIR)/vpn/node.def
 	rm -f $(TMPL_DIR)/vpn/ipsec/node.def
 
 .PHONY: op_mode_definitions
 .ONESHELL:
 op_mode_definitions:
 	mkdir -p $(OP_TMPL_DIR)
 
 	find $(CURDIR)/op-mode-definitions/ -type f -name "*.xml" | xargs -I {} $(CURDIR)/scripts/build-command-op-templates {} $(CURDIR)/schema/op-mode-definition.rng $(OP_TMPL_DIR) || exit 1
 
 	# XXX: delete top level op mode node.def's that now live in other packages
 	rm -f $(OP_TMPL_DIR)/clear/node.def
 	rm -f $(OP_TMPL_DIR)/clear/interfaces/node.def
 	rm -f $(OP_TMPL_DIR)/set/node.def
 	rm -f $(OP_TMPL_DIR)/show/node.def
 	rm -f $(OP_TMPL_DIR)/show/interfaces/node.def
 	rm -f $(OP_TMPL_DIR)/show/ip/node.def
 	rm -f $(OP_TMPL_DIR)/show/ip/route/node.def
 	rm -f $(OP_TMPL_DIR)/show/ipv6/node.def
 	rm -f $(OP_TMPL_DIR)/show/ipv6/route/node.def
 	rm -f $(OP_TMPL_DIR)/restart/node.def
 	rm -f $(OP_TMPL_DIR)/monitor/node.def
 	rm -f $(OP_TMPL_DIR)/generate/node.def
 	rm -f $(OP_TMPL_DIR)/show/vpn/node.def
 	rm -f $(OP_TMPL_DIR)/show/system/node.def
 	rm -f $(OP_TMPL_DIR)/delete/node.def
 	rm -f $(OP_TMPL_DIR)/reset/vpn/node.def
 	rm -f $(OP_TMPL_DIR)/show/system/node.def
 
 .PHONY: all
 all: clean interface_definitions op_mode_definitions
 
 .PHONY: clean
 clean:
 	rm -rf $(BUILD_DIR)
 	rm -rf $(TMPL_DIR)
 	rm -rf $(OP_TMPL_DIR)
 
 .PHONY: test
 test:
 	PYTHONPATH=python/ python3 -m "nose" --with-xunit src --with-coverage --cover-erase --cover-xml --cover-package src/conf_mode,src/op_mode,src/completion,src/helpers,src/validators,src/tests --verbose
 
 .PHONY: sonar
 sonar:
 	sonar-scanner -X -Dsonar.login=${SONAR_TOKEN}
 
 .PHONY: docs
 .ONESHELL:
 docs:
 	sphinx-apidoc -o sphinx/source/  python/
 	cd sphinx/
 	PYTHONPATH=../python make html
diff --git a/interface-definitions/system-proxy.xml.in b/interface-definitions/system-proxy.xml.in
index 4b21139a6..540fa97e3 100644
--- a/interface-definitions/system-proxy.xml.in
+++ b/interface-definitions/system-proxy.xml.in
@@ -1,43 +1,43 @@
 <?xml version="1.0"?>
 <interfaceDefinition>
   <node name="system">
     <children>
       <node name="proxy" owner="${vyos_conf_scripts_dir}/system-proxy.py">
         <properties>
           <help>Sets a proxy for system wide use</help>
         </properties>
         <children>
           <leafNode name="url">
             <properties>
               <help>Proxy URL</help>
               <constraint>
-                <regex>http://[a-z0-9\.]+$</regex>
+                <regex>http:\/\/[a-z0-9\.]+$</regex>
               </constraint>
             </properties>
           </leafNode>
           <leafNode name="port">
             <properties>
               <help>Proxy port</help>
               <constraint>
                 <validator name="numeric" argument="--range 1-65535"/>
               </constraint>
             </properties>
           </leafNode>
           <leafNode name="username">
             <properties>
               <help>Proxy username</help>
               <constraint>
-                <regex>^[a-z0-9-_\.]{1,100}$</regex>
+                <regex>[a-z0-9-_\.]{1,100}$</regex>
               </constraint>
             </properties>
           </leafNode>
           <leafNode name="password">
             <properties>
               <help>Proxy password</help>
             </properties>
           </leafNode>
         </children>
       </node>
     </children>
   </node>
 </interfaceDefinition>