diff --git a/cue/load/config.go b/cue/load/config.go
index 46ff754..2da8efb 100644
--- a/cue/load/config.go
+++ b/cue/load/config.go
@@ -19,6 +19,7 @@
 	"path/filepath"
 	"runtime"
 
+	"cuelang.org/go/cue"
 	"cuelang.org/go/cue/build"
 	"cuelang.org/go/cue/errors"
 	"cuelang.org/go/cue/token"
@@ -75,7 +76,14 @@
 
 	loader *loader
 
-	modRoot string // module root for package paths ("" if unknown)
+	// A Module is a collection of packages and instances that are within the
+	// directory hierarchy rooted at the module root. The module root can be
+	// marked with a cue.mod file.
+	ModuleRoot string
+
+	// Module specifies the module prefix. If not empty, this value must match
+	// the module field of an existing cue.mod file.
+	Module string
 
 	// cache specifies the package cache in which to look for packages.
 	cache string
@@ -173,13 +181,13 @@
 	// TODO: determine root on a package basis. Maybe we even need a
 	// pkgname.cue.mod
 	// Look to see if there is a cue.mod.
-	if c.modRoot == "" {
+	if c.ModuleRoot == "" {
 		abs, err := c.findRoot(c.Dir)
 		if err != nil {
 			// Not using modules: only consider the current directory.
-			c.modRoot = c.Dir
+			c.ModuleRoot = c.Dir
 		} else {
-			c.modRoot = abs
+			c.ModuleRoot = abs
 		}
 	}
 
@@ -193,6 +201,32 @@
 		c.cache = filepath.Join(home(), defaultDir)
 	}
 
+	// TODO: also make this work if run from outside the module?
+	switch {
+	case true:
+		mod := filepath.Join(c.ModuleRoot, modFile)
+		f, cerr := c.fileSystem.openFile(mod)
+		if cerr != nil {
+			break
+		}
+		var r cue.Runtime
+		inst, err := r.Parse(mod, f)
+		if err != nil {
+			return nil, errors.Wrapf(err, token.NoPos, "invalid cue.mod file")
+		}
+		prefix := inst.Lookup("module")
+		if prefix.IsValid() {
+			name, err := prefix.String()
+			if err != nil {
+				return nil, err
+			}
+			if c.Module == "" || c.Module != name {
+				return nil, errors.Newf(prefix.Pos(), "inconsistent modules: got %q, want %q", name, c.Module)
+			}
+			c.Module = name
+		}
+	}
+
 	return &c, nil
 }
 
diff --git a/cue/load/import.go b/cue/load/import.go
index 11f6a6e..9607252 100644
--- a/cue/load/import.go
+++ b/cue/load/import.go
@@ -81,6 +81,11 @@
 	p.DisplayPath = path
 
 	isLocal := isLocalImport(path)
+
+	if cfg.Module != "" && isLocal {
+		p.ImportPath = filepath.Join(cfg.Module, path)
+	}
+
 	var modDir string
 	// var modErr error
 	if !isLocal {
@@ -125,7 +130,7 @@
 			}
 		}
 
-		if rootFound || dir == p.Root || fp.pkg.PkgName == "" {
+		if rootFound || filepath.Clean(dir) == l.cfg.ModuleRoot || fp.pkg.PkgName == "" {
 			break
 		}
 
@@ -176,13 +181,19 @@
 				}
 				return nil
 			}
-			if cfg.modRoot == "" {
+			if cfg.ModuleRoot == "" {
 				i := cfg.newInstance(path)
 				report(i, l.errPkgf(nil,
 					"import %q not found in the pkg directory", path))
 				return i
 			}
-			return l.importPkg(pos, path, filepath.Join(cfg.modRoot, "pkg"))
+			root := cfg.ModuleRoot
+			if mod := cfg.Module; path == mod || strings.HasPrefix(path, mod+"/") {
+				path = path[len(mod)+1:]
+			} else {
+				root = filepath.Join(root, "pkg")
+			}
+			return l.importPkg(pos, path, root)
 		}
 
 		if strings.Contains(path, "@") {
diff --git a/cue/load/loader.go b/cue/load/loader.go
index 4753763..aa8e38b 100644
--- a/cue/load/loader.go
+++ b/cue/load/loader.go
@@ -42,7 +42,7 @@
 
 	c, err := c.complete()
 	if err != nil {
-		return nil
+		return []*build.Instance{c.newErrInstance(nil, "", err)}
 	}
 
 	l := c.loader
@@ -57,8 +57,7 @@
 	a := []*build.Instance{}
 	for _, m := range l.importPaths(args) {
 		if m.Err != nil {
-			inst := c.newErrInstance(m, "",
-				errors.Wrapf(m.Err, token.NoPos, "no match"))
+			inst := c.newErrInstance(m, "", m.Err)
 			a = append(a, inst)
 			continue
 		}
diff --git a/cue/load/search.go b/cue/load/search.go
index da43ad5..3f2d0de 100644
--- a/cue/load/search.go
+++ b/cue/load/search.go
@@ -148,11 +148,11 @@
 
 	root := l.abs(dir)
 
-	if c.modRoot != "" {
-		if !hasFilepathPrefix(root, c.modRoot) {
+	if c.ModuleRoot != "" {
+		if !hasFilepathPrefix(root, c.ModuleRoot) {
 			m.Err = errors.Newf(token.NoPos,
 				"cue: pattern %s refers to dir %s, outside module root %s",
-				pattern, root, c.modRoot)
+				pattern, root, c.ModuleRoot)
 			return m
 		}
 	}