diff --git a/src/cmd/go/internal/modload/load.go b/src/cmd/go/internal/modload/load.go
index e74780a7b28..afd6c80370c 100644
--- a/src/cmd/go/internal/modload/load.go
+++ b/src/cmd/go/internal/modload/load.go
@@ -753,6 +753,7 @@ func (mms *MainModuleSet) DirImportPath(ctx context.Context, dir string) (path s
 				suffix := filepath.ToSlash(dir[len(modRoot):])
 				if strings.HasPrefix(suffix, "/vendor/") {
 					longestPrefixPath = strings.TrimPrefix(suffix, "/vendor/")
+					continue
 				}
 				longestPrefixPath = mms.PathPrefix(v) + suffix
 			}
diff --git a/src/cmd/go/testdata/script/vendor_internal.txt b/src/cmd/go/testdata/script/vendor_internal.txt
new file mode 100644
index 00000000000..4c0f1facee9
--- /dev/null
+++ b/src/cmd/go/testdata/script/vendor_internal.txt
@@ -0,0 +1,16 @@
+go build ./vendor/foo.com/internal/bar/a
+
+-- go.mod --
+module example.com/x
+go 1.19
+
+require "foo.com/internal/bar" v1.0.0
+-- vendor/modules.txt --
+# foo.com/internal/bar v1.0.0
+## explicit
+foo.com/internal/bar/a
+-- vendor/foo.com/internal/bar/a/a.go --
+package a
+import _ "foo.com/internal/bar/b"
+-- vendor/foo.com/internal/bar/b/b.go --
+package b
\ No newline at end of file