diff --git a/Gruntfile.js b/Gruntfile.js
index 60b474103..fc881ddee 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -110,13 +110,13 @@ module.exports = function(grunt) {
                     "editor/js/nodes.js",
                     "editor/js/history.js",
                     "editor/js/validators.js",
+                    "editor/js/ui/utils.js",
                     "editor/js/ui/common/editableList.js",
                     "editor/js/ui/common/menu.js",
                     "editor/js/ui/common/popover.js",
                     "editor/js/ui/common/searchBox.js",
                     "editor/js/ui/common/tabs.js",
                     "editor/js/ui/common/typedInput.js",
-                    "editor/js/ui/utils.js",
                     "editor/js/ui/actions.js",
                     "editor/js/ui/deploy.js",
                     "editor/js/ui/diff.js",
diff --git a/editor/js/ui/common/typedInput.js b/editor/js/ui/common/typedInput.js
index e7a26cf3d..06359a9ec 100644
--- a/editor/js/ui/common/typedInput.js
+++ b/editor/js/ui/common/typedInput.js
@@ -14,82 +14,13 @@
  * limitations under the License.
  **/
 (function($) {
-    function validateExpression(str) {
-        var length = str.length;
-        var start = 0;
-        var inString = false;
-        var inBox = false;
-        var quoteChar;
-        var v;
-        for (var i=0;i<length;i++) {
-            var c = str[i];
-            if (!inString) {
-                if (c === "'" || c === '"') {
-                    if (!inBox) {
-                        return false;
-                    }
-                    inString = true;
-                    quoteChar = c;
-                    start = i+1;
-                } else if (c === '.') {
-                    if (i===0 || i===length-1) {
-                        return false;
-                    }
-                    // Next char is a-z
-                    if (!/[a-z0-9]/i.test(str[i+1])) {
-                        return false;
-                    }
-                    start = i+1;
-                } else if (c === '[') {
-                    if (i === 0) {
-                        return false;
-                    }
-                    if (i===length-1) {
-                        return false;
-                    }
-                    // Next char is either a quote or a number
-                    if (!/["'\d]/.test(str[i+1])) {
-                        return false;
-                    }
-                    start = i+1;
-                    inBox = true;
-                } else if (c === ']') {
-                    if (!inBox) {
-                        return false;
-                    }
-                    if (start != i) {
-                        v = str.substring(start,i);
-                        if (!/^\d+$/.test(v)) {
-                            return false;
-                        }
-                    }
-                    start = i+1;
-                    inBox = false;
-                } else if (c === ' ') {
-                    return false;
-                }
-            } else {
-                if (c === quoteChar) {
-                    // Next char must be a ]
-                    if (!/\]/.test(str[i+1])) {
-                        return false;
-                    }
-                    start = i+1;
-                    inString = false;
-                }
-            }
 
-        }
-        if (inBox || inString) {
-            return false;
-        }
-        return true;
-    }
+
 
     var allOptions = {
-        msg: {value:"msg",label:"msg.",validate:validateExpression},
-        flow: {value:"flow",label:"flow.",validate:validateExpression},
-        global: {value:"global",label:"global.",validate:validateExpression},
+        msg: {value:"msg",label:"msg.",validate:RED.utils.validatePropertyExpression},
+        flow: {value:"flow",label:"flow.",validate:RED.utils.validatePropertyExpression},
+        global: {value:"global",label:"global.",validate:RED.utils.validatePropertyExpression},
         str: {value:"str",label:"string",icon:"red/images/typedInput/az.png"},
         num: {value:"num",label:"number",icon:"red/images/typedInput/09.png",validate:/^[+-]?[0-9]*\.?[0-9]*([eE][-+]?[0-9]+)?$/},
         bool: {value:"bool",label:"boolean",icon:"red/images/typedInput/bool.png",options:["true","false"]},
diff --git a/editor/js/ui/utils.js b/editor/js/ui/utils.js
index d81924b81..ef88bdb09 100644
--- a/editor/js/ui/utils.js
+++ b/editor/js/ui/utils.js
@@ -279,7 +279,88 @@ RED.utils = (function() {
         return element;
     }
 
+    function validatePropertyExpression(str) {
+        // This must be kept in sync with normalisePropertyExpression
+        // in red/runtime/util.js
+
+        var length = str.length;
+        var start = 0;
+        var inString = false;
+        var inBox = false;
+        var quoteChar;
+        var v;
+        for (var i=0;i<length;i++) {
+            var c = str[i];
+            if (!inString) {
+                if (c === "'" || c === '"') {
+                    if (i != start) {
+                        return false;
+                    }
+                    inString = true;
+                    quoteChar = c;
+                    start = i+1;
+                } else if (c === '.') {
+                    if (i===0 || i===length-1) {
+                        return false;
+                    }
+                    // Next char is a-z
+                    if (!/[a-z0-9]/i.test(str[i+1])) {
+                        return false;
+                    }
+                    start = i+1;
+                } else if (c === '[') {
+                    if (i === 0) {
+                        return false;
+                    }
+                    if (i===length-1) {
+                        return false;
+                    }
+                    // Next char is either a quote or a number
+                    if (!/["'\d]/.test(str[i+1])) {
+                        return false;
+                    }
+                    start = i+1;
+                    inBox = true;
+                } else if (c === ']') {
+                    if (!inBox) {
+                        return false;
+                    }
+                    if (start != i) {
+                        v = str.substring(start,i);
+                        if (!/^\d+$/.test(v)) {
+                            return false;
+                        }
+                    }
+                    start = i+1;
+                    inBox = false;
+                } else if (c === ' ') {
+                    return false;
+                }
+            } else {
+                if (c === quoteChar) {
+                    if (i-start === 0) {
+                        return false;
+                    }
+                    // Next char must be a ]
+                    if (inBox && !/\]/.test(str[i+1])) {
+                        return false;
+                    } else if (!inBox && i+1!==length && !/[\[\.]/.test(str[i+1])) {
+                        return false;
+                    }
+                    start = i+1;
+                    inString = false;
+                }
+            }
+
+        }
+        if (inBox || inString) {
+            return false;
+        }
+        return true;
+    }
+
     return {
         createObjectElement: buildMessageElement,
+        validatePropertyExpression: validatePropertyExpression
     }
 })();
diff --git a/nodes/core/core/20-inject.html b/nodes/core/core/20-inject.html
index 14117e16d..a362ecedd 100644
--- a/nodes/core/core/20-inject.html
+++ b/nodes/core/core/20-inject.html
@@ -185,7 +185,7 @@
                         return false;
                     }
                 } else if (ptype === 'flow' || ptype === 'global' ) {
-                    return /^[a-zA-Z_][a-zA-Z0-9_]*(\.[a-zA-Z_][a-zA-Z0-9_]+)*/i.test(v);
+                    return RED.utils.validatePropertyExpression(v);
                 } else if (ptype === 'num') {
                     return /^[+-]?[0-9]*\.?[0-9]*([eE][-+]?[0-9]+)?$/.test(v);
                 }
diff --git a/red/runtime/util.js b/red/runtime/util.js
index 97213a389..5c2661925 100644
--- a/red/runtime/util.js
+++ b/red/runtime/util.js
@@ -129,6 +129,9 @@ function compareObjects(obj1,obj2) {
 }
 
 function normalisePropertyExpression(str) {
+    // This must be kept in sync with validatePropertyExpression
+    // in editor/js/ui/utils.js
+
     var length = str.length;
     var parts = [];
     var start = 0;
@@ -140,7 +143,7 @@ function normalisePropertyExpression(str) {
         var c = str[i];
         if (!inString) {
             if (c === "'" || c === '"') {
-                if (!inBox) {
+                if (i != start) {
                     throw new Error("Invalid property expression: unexpected "+c+" at position "+i);
                 }
                 inString = true;
@@ -201,10 +204,15 @@ function normalisePropertyExpression(str) {
             }
         } else {
             if (c === quoteChar) {
+                if (i-start === 0) {
+                    throw new Error("Invalid property expression: zero-length string at position "+start);
+                }
                 parts.push(str.substring(start,i));
-                // Next char must be a ]
-                if (!/\]/.test(str[i+1])) {
+                // If inBox, next char must be a ]. Otherwise it may be [ or .
+                if (inBox && !/\]/.test(str[i+1])) {
                     throw new Error("Invalid property expression: unexpected array expression at position "+start);
+                } else if (!inBox && i+1!==length && !/[\[\.]/.test(str[i+1])) {
+                    throw new Error("Invalid property expression: unexpected "+str[i+1]+" expression at position "+(i+1));
                 }
                 start = i+1;
                 inString = false;
diff --git a/test/red/runtime/util_spec.js b/test/red/runtime/util_spec.js
index aa8e25728..140f894de 100644
--- a/test/red/runtime/util_spec.js
+++ b/test/red/runtime/util_spec.js
@@ -332,6 +332,10 @@ describe("red/util", function() {
         it("pass a.0.c",function() { testABC("a.0.c",['a',0,'c']); })
         it("pass a['a.b[0]'].c",function() { testABC("a['a.b[0]'].c",['a','a.b[0]','c']); })
         it("pass a[0][0][0]",function() { testABC("a[0][0][0]",['a',0,0,0]); })
+        it("pass '1.2.3.4'",function() { testABC("'1.2.3.4'",['1.2.3.4']); })
+        it("pass 'a.b'[1]",function() { testABC("'a.b'[1]",['a.b',1]); })
+        it("pass 'a.b'.c",function() { testABC("'a.b'.c",['a.b','c']); })
+
 
         it("fail a'b'.c",function() { testInvalid("a'b'.c"); })
         it("fail a['b'.c",function() { testInvalid("a['b'.c"); })
@@ -350,5 +354,8 @@ describe("red/util", function() {
         it("fail a. b",function() { testInvalid("a. b"); })
         it("fail  a.b",function() { testInvalid(" a.b"); })
         it("fail a[0].[1]",function() { testInvalid("a[0].[1]"); })
+        it("fail a['']",function() { testInvalid("a['']"); })
+        it("fail 'a.b'c",function() { testInvalid("'a.b'c"); })
+
     });
 });