diff --git a/interface-definitions/container.xml.in b/interface-definitions/container.xml.in
index ad18156047..04318a7c9d 100644
--- a/interface-definitions/container.xml.in
+++ b/interface-definitions/container.xml.in
@@ -131,7 +131,7 @@
             <properties>
               <help>Add custom environment variables</help>
               <constraint>
-                <regex>[-_a-zA-Z0-9]+</regex>
+                #include <include/constraint/alpha-numeric-hyphen-underscore.xml.i>
               </constraint>
               <constraintErrorMessage>Environment variable name must be alphanumeric and can contain hyphen and underscores</constraintErrorMessage>
             </properties>
diff --git a/interface-definitions/include/haproxy/rule-backend.xml.i b/interface-definitions/include/haproxy/rule-backend.xml.i
index b2be4fde4d..1df9d5dcfb 100644
--- a/interface-definitions/include/haproxy/rule-backend.xml.i
+++ b/interface-definitions/include/haproxy/rule-backend.xml.i
@@ -47,7 +47,7 @@
           <properties>
             <help>Server name</help>
             <constraint>
-              <regex>[-_a-zA-Z0-9]+</regex>
+              #include <include/constraint/alpha-numeric-hyphen-underscore.xml.i>
             </constraint>
             <constraintErrorMessage>Server name must be alphanumeric and can contain hyphen and underscores</constraintErrorMessage>
           </properties>
diff --git a/interface-definitions/include/haproxy/rule-frontend.xml.i b/interface-definitions/include/haproxy/rule-frontend.xml.i
index 001ae2d806..aeee1202e7 100644
--- a/interface-definitions/include/haproxy/rule-frontend.xml.i
+++ b/interface-definitions/include/haproxy/rule-frontend.xml.i
@@ -47,7 +47,7 @@
           <properties>
             <help>Backend name</help>
             <constraint>
-              <regex>[-_a-zA-Z0-9]+</regex>
+              #include <include/constraint/alpha-numeric-hyphen-underscore.xml.i>
             </constraint>
             <constraintErrorMessage>Server name must be alphanumeric and can contain hyphen and underscores</constraintErrorMessage>
           </properties>