diff --git a/docshell/base/nsDefaultURIFixup.cpp b/docshell/base/nsDefaultURIFixup.cpp
index 6b75bde30003..81b077121bc4 100644
--- a/docshell/base/nsDefaultURIFixup.cpp
+++ b/docshell/base/nsDefaultURIFixup.cpp
@@ -748,13 +748,13 @@ bool nsDefaultURIFixup::PossiblyHostPortUrl(const nsACString& aUrl) {
   ++iter;
 
   // Count the number of digits after the colon and before the
-  // next forward slash (or end of string)
+  // next forward slash, question mark, hash sign, or end of string.
 
   uint32_t digitCount = 0;
   while (iter != iterEnd && digitCount <= 5) {
     if (IsAsciiDigit(*iter)) {
       digitCount++;
-    } else if (*iter == '/') {
+    } else if (*iter == '/' || *iter == '?' || *iter == '#') {
       break;
     } else {
       // Whatever it is, it ain't a port!
diff --git a/docshell/test/unit/test_nsDefaultURIFixup_search.js b/docshell/test/unit/test_nsDefaultURIFixup_search.js
index df8c26d9a1bc..150adfd56033 100644
--- a/docshell/test/unit/test_nsDefaultURIFixup_search.js
+++ b/docshell/test/unit/test_nsDefaultURIFixup_search.js
@@ -83,6 +83,18 @@ var data = [
     wrong: "://user:pass@example.com:8080/this/is/a/test.html",
     fixed: "http://user:pass@example.com:8080/this/is/a/test.html",
   },
+  {
+    wrong: "localhost:8080/?param=1",
+    fixed: "http://localhost:8080/?param=1",
+  },
+  {
+    wrong: "localhost:8080?param=1",
+    fixed: "http://localhost:8080/?param=1",
+  },
+  {
+    wrong: "localhost:8080#somewhere",
+    fixed: "http://localhost:8080/#somewhere",
+  },
   {
     wrong: "whatever://this/is/a@b/test.html",
     fixed: kSearchEngineURL.replace(