diff --git a/api/internal/git/repospec.go b/api/internal/git/repospec.go
index d08d842e8..b82c5f7d8 100644
--- a/api/internal/git/repospec.go
+++ b/api/internal/git/repospec.go
@@ -244,9 +244,10 @@ func extractHost(n string) (string, string) {
 
 	// Now that we have extracted a valid scheme+username, we can parse host itself.
 
-	// The file protocol specifies an absolute path to a local git repo. There is no host.
+	// The file protocol specifies an absolute path to a local git repo.
+	// Everything after the scheme (including any 'username' we found) is actually part of that path.
 	if scheme == "file://" {
-		return scheme, n
+		return scheme, username + n
 	}
 	sepIndex := findPathSeparator(n, acceptSCP)
 	host, rest := n[:sepIndex+1], n[sepIndex+1:]
@@ -300,8 +301,12 @@ func validateUsernameAndScheme(username, scheme string, acceptSCPStyle bool) err
 	case "ssh://":
 		// usernames are optional for ssh protocol
 		return nil
-	case "https://", "http://", "file://":
-		// usernames are not supported by http or file protocols
+	case "file://":
+		// everything following the scheme in the file protocol is a path on the local filesystem,
+		// which may contain arbitrary characters (theoretically including `@`, which we'd mistake for a username)
+		return nil
+	case "https://", "http://":
+		// usernames are not supported by the http protocol
 		if username != "" {
 			return fmt.Errorf("username %q specified, but %s does not support usernames", username, scheme)
 		}
diff --git a/api/internal/git/repospec_test.go b/api/internal/git/repospec_test.go
index 6f79e9822..a3f01e88c 100644
--- a/api/internal/git/repospec_test.go
+++ b/api/internal/git/repospec_test.go
@@ -128,10 +128,6 @@ func TestNewRepoSpecFromUrlErrors(t *testing.T) {
 			"https://git@foo.com/path/to/repo",
 			"url lacks host",
 		},
-		"username unsupported with file": {
-			"file://git@/path/to/repo",
-			"url lacks repoPath",
-		},
 	}
 
 	for name, testCase := range badData {
@@ -512,6 +508,19 @@ func TestNewRepoSpecFromUrl_Smoke(t *testing.T) {
 				GitSuffix:    ".git",
 			},
 		},
+		{
+			name:      "username-like filepath with file protocol",
+			input:     "file://git@home/path/to/repository.git//path?ref=branch",
+			cloneSpec: "file://git@home/path/to/repository.git",
+			absPath:   notCloned.Join("path"),
+			repoSpec: RepoSpec{
+				Host:         "file://",
+				RepoPath:     "git@home/path/to/repository",
+				KustRootPath: "/path",
+				Ref:          "branch",
+				GitSuffix:    ".git",
+			},
+		},
 		{
 			name:      "unsupported protocol after username (invalid and will be rejected by git)",
 			input:     "git@scp://github.com/org/repo.git//path",