diff --git a/src/cmd/compile/internal/gc/pgen.go b/src/cmd/compile/internal/gc/pgen.go
index a1665ea0220..5d77ec66aa4 100644
--- a/src/cmd/compile/internal/gc/pgen.go
+++ b/src/cmd/compile/internal/gc/pgen.go
@@ -423,6 +423,7 @@ func compile(fn *Node) {
 			fallthrough
 		case PPARAM, PPARAMOUT:
 			p := Gins(obj.ATYPE, n, nil)
+			p.From.Sym = obj.Linklookup(Ctxt, n.Sym.Name, 0)
 			p.To.Type = obj.TYPE_MEM
 			p.To.Name = obj.NAME_EXTERN
 			p.To.Sym = Linksym(ngotype(n))
diff --git a/src/cmd/internal/dwarf/dwarf.go b/src/cmd/internal/dwarf/dwarf.go
index 58dcf4e55d5..725f5027bb5 100644
--- a/src/cmd/internal/dwarf/dwarf.go
+++ b/src/cmd/internal/dwarf/dwarf.go
@@ -588,11 +588,6 @@ func PutFunc(ctxt Context, s Sym, name string, external bool, startPC Sym, size
 		}
 		names[n] = true
 
-		// Drop the package prefix from locals and arguments.
-		if i := strings.LastIndex(n, "."); i >= 0 {
-			n = n[i+1:]
-		}
-
 		Uleb128put(ctxt, s, int64(v.Abbrev))
 		putattr(ctxt, s, v.Abbrev, DW_FORM_string, DW_CLS_STRING, int64(len(n)), n)
 		loc := append(encbuf[:0], DW_OP_call_frame_cfa)
diff --git a/src/runtime/runtime-gdb_test.go b/src/runtime/runtime-gdb_test.go
index ba005ac35b5..3f2d74248ba 100644
--- a/src/runtime/runtime-gdb_test.go
+++ b/src/runtime/runtime-gdb_test.go
@@ -68,14 +68,18 @@ func checkGdbPython(t *testing.T) {
 const helloSource = `
 package main
 import "fmt"
+var gslice []string
 func main() {
 	mapvar := make(map[string]string,5)
 	mapvar["abc"] = "def"
 	mapvar["ghi"] = "jkl"
 	strvar := "abc"
 	ptrvar := &strvar
-	fmt.Println("hi") // line 10
+	slicevar := make([]string, 0, 16)
+	slicevar = append(slicevar, mapvar["abc"])
+	fmt.Println("hi") // line 12
 	_ = ptrvar
+	gslice = slicevar
 }
 `
 
@@ -120,6 +124,9 @@ func TestGdbPython(t *testing.T) {
 		"-ex", "echo BEGIN print strvar\n",
 		"-ex", "print strvar",
 		"-ex", "echo END\n",
+		"-ex", "echo BEGIN info locals\n",
+		"-ex", "info locals",
+		"-ex", "echo END\n",
 		"-ex", "down", // back to fmt.Println (goroutine 2 below only works at bottom of stack.  TODO: fix that)
 		"-ex", "echo BEGIN goroutine 2 bt\n",
 		"-ex", "goroutine 2 bt",
@@ -168,6 +175,15 @@ func TestGdbPython(t *testing.T) {
 		t.Fatalf("print strvar failed: %s", bl)
 	}
 
+	// Issue 16338: ssa decompose phase can split a structure into
+	// a collection of scalar vars holding the fields. In such cases
+	// the DWARF variable location expression should be of the
+	// form "var.field" and not just "field".
+	infoLocalsRe := regexp.MustCompile(`^slicevar.len = `)
+	if bl := blocks["info locals"]; !infoLocalsRe.MatchString(bl) {
+		t.Fatalf("info locals failed: %s", bl)
+	}
+
 	btGoroutineRe := regexp.MustCompile(`^#0\s+runtime.+at`)
 	if bl := blocks["goroutine 2 bt"]; !btGoroutineRe.MatchString(bl) {
 		t.Fatalf("goroutine 2 bt failed: %s", bl)