--- a/browser/extensions/formautofill/FormAutofillUtils.jsm
+++ b/browser/extensions/formautofill/FormAutofillUtils.jsm
@@ -65,20 +65,20 @@ this.FormAutofillUtils = {
     // white space is a temporary solution.
     return " ";
   },
 
   toOneLineAddress(address, delimiter = "\n") {
     let array = typeof address == "string" ? address.split(delimiter) : address;
 
     if (!Array.isArray(array)) {
-      return null;
+      return "";
     }
     return array
-      .map(s => s.trim())
+      .map(s => s ? s.trim() : "")
       .filter(s => s)
       .join(this.getAddressSeparator());
   },
 
   defineLazyLogGetter(scope, logPrefix) {
     XPCOMUtils.defineLazyGetter(scope, "log", () => {
       let ConsoleAPI = Cu.import("resource://gre/modules/Console.jsm", {}).ConsoleAPI;
       return new ConsoleAPI({

--- a/browser/extensions/formautofill/content/manageProfiles.js
+++ b/browser/extensions/formautofill/content/manageProfiles.js
@@ -136,29 +136,29 @@ ManageProfileDialog.prototype = {
    * @returns {string}
    */
   getAddressLabel(address) {
     // TODO: Implement a smarter way for deciding what to display
     //       as option text. Possibly improve the algorithm in
     //       ProfileAutoCompleteResult.jsm and reuse it here.
     const fieldOrder = [
       "name",
-      "street-address",  // Street address
+      "-moz-street-address-one-line",  // Street address
       "address-level2",  // City/Town
       "organization",    // Company or organization name
       "address-level1",  // Province/State (Standardized code if possible)
       "country-name",    // Country name
       "postal-code",     // Postal code
       "tel",             // Phone number
       "email",           // Email address
     ];
 
     let parts = [];
     if (address["street-address"]) {
-      address["street-address"] = FormAutofillUtils.toOneLineAddress(
+      address["-moz-street-address-one-line"] = FormAutofillUtils.toOneLineAddress(
         address["street-address"]
       );
     }
     for (const fieldName of fieldOrder) {
       let string = address[fieldName];
       if (string) {
         parts.push(string);
       }

--- a/browser/extensions/formautofill/test/unit/test_toOneLineAddress.js
+++ b/browser/extensions/formautofill/test/unit/test_toOneLineAddress.js
@@ -13,16 +13,20 @@ add_task(async function test_getCategori
       strings: ["A", "B", "", "D"],
       expectedValue: "A B D",
     },
     {
       strings: ["", "B", "", "D"],
       expectedValue: "B D",
     },
     {
+      strings: [null, "B", " ", "D"],
+      expectedValue: "B D",
+    },
+    {
       strings: "A B C",
       expectedValue: "A B C",
     },
     {
       strings: "A\nB\n\n\nC",
       expectedValue: "A B C",
     },
     {
@@ -33,20 +37,24 @@ add_task(async function test_getCategori
       strings: "A-B-C",
       expectedValue: "A B C",
       delimiter: "-",
     },
     {
       strings: "A B\n \nC",
       expectedValue: "A B C",
     },
+    {
+      strings: null,
+      expectedValue: "",
+    },
   ];
 
   for (let tc of TEST_CASES) {
     let result;
     if (tc.delimiter) {
       result = FormAutofillUtils.toOneLineAddress(tc.strings, tc.delimiter);
     } else {
       result = FormAutofillUtils.toOneLineAddress(tc.strings);
     }
-    Assert.deepEqual(result, tc.expectedValue);
+    Assert.equal(result, tc.expectedValue);
   }
 });