diff --git a/hcl2template/common_test.go b/hcl2template/common_test.go
index c3b17b817..fe2a8afc7 100644
--- a/hcl2template/common_test.go
+++ b/hcl2template/common_test.go
@@ -60,7 +60,7 @@ func testParse(t *testing.T, tests []parseTest) {
 		t.Run(tt.name, func(t *testing.T) {
 			gotCfg, gotDiags := tt.parser.parse(tt.args.filename, tt.args.vars)
 			if tt.parseWantDiags == (gotDiags == nil) {
-				t.Fatalf("Parser.parse() unexpected diagnostics. %s", gotDiags)
+				t.Fatalf("Parser.parse() unexpected %q diagnostics.", gotDiags)
 			}
 			if tt.parseWantDiagHasErrors != gotDiags.HasErrors() {
 				t.Fatalf("Parser.parse() unexpected diagnostics HasErrors. %s", gotDiags)
@@ -97,6 +97,7 @@ func testParse(t *testing.T, tests []parseTest) {
 					packer.CoreBuild{},
 					packer.CoreBuildProvisioner{},
 					packer.CoreBuildPostProcessor{},
+					null.Builder{},
 				),
 			); diff != "" {
 				t.Fatalf("Parser.getBuilds() wrong packer builds. %s", diff)
diff --git a/hcl2template/parser.go b/hcl2template/parser.go
index cf7af9fd4..071bf6206 100644
--- a/hcl2template/parser.go
+++ b/hcl2template/parser.go
@@ -101,10 +101,10 @@ func (p *Parser) parse(filename string, vars map[string]string) (*PackerConfig,
 		}
 	}
 
-	_, moreDiags := cfg.InputVariables.Values()
-	diags = append(diags, moreDiags...)
-	_, moreDiags = cfg.LocalVariables.Values()
-	diags = append(diags, moreDiags...)
+	// _, moreDiags := cfg.InputVariables.Values()
+	// diags = append(diags, moreDiags...)
+	// _, moreDiags = cfg.LocalVariables.Values()
+	// diags = append(diags, moreDiags...)
 
 	// parse var files
 	{
diff --git a/hcl2template/testdata/variables/unset_unused_string_variable.pkr.hcl b/hcl2template/testdata/variables/unset_unused_string_variable.pkr.hcl
new file mode 100644
index 000000000..1853a09d2
--- /dev/null
+++ b/hcl2template/testdata/variables/unset_unused_string_variable.pkr.hcl
@@ -0,0 +1,15 @@
+
+variable "foo" {
+  type = string
+}
+
+
+build {
+  sources = [
+    "source.null.null-builder",
+  ]
+}
+
+source "null" "null-builder" {
+  communicator = "none"
+}
diff --git a/hcl2template/testdata/variables/unset_string_variable.pkr.hcl b/hcl2template/testdata/variables/unset_used_string_variable.pkr.hcl
similarity index 100%
rename from hcl2template/testdata/variables/unset_string_variable.pkr.hcl
rename to hcl2template/testdata/variables/unset_used_string_variable.pkr.hcl
diff --git a/hcl2template/types.variables.go b/hcl2template/types.variables.go
index 29112cda7..29e4d51d6 100644
--- a/hcl2template/types.variables.go
+++ b/hcl2template/types.variables.go
@@ -59,7 +59,12 @@ func (v *Variable) Value() (cty.Value, *hcl.Diagnostic) {
 		}
 	}
 
-	return cty.UnknownVal(v.Type), &hcl.Diagnostic{
+	value := cty.NullVal(cty.DynamicPseudoType)
+	if v.Type != cty.NilType {
+		cty.NullVal(v.Type)
+	}
+
+	return value, &hcl.Diagnostic{
 		Severity: hcl.DiagError,
 		Summary:  fmt.Sprintf("Unset variable %q", v.Name),
 		Detail: "A used variable must be set or have a default value; see " +
@@ -248,6 +253,7 @@ func (variables Variables) collectVariableValues(env []string, files []*hcl.File
 		if moreDiags.HasErrors() {
 			continue
 		}
+
 		val, valDiags := expr.Value(nil)
 		diags = append(diags, valDiags...)
 
diff --git a/hcl2template/types.variables_test.go b/hcl2template/types.variables_test.go
index 687f8f5a4..8c3894927 100644
--- a/hcl2template/types.variables_test.go
+++ b/hcl2template/types.variables_test.go
@@ -10,6 +10,7 @@ import (
 	"github.com/zclconf/go-cty/cty/convert"
 
 	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/packer/builder/null"
 	"github.com/hashicorp/packer/packer"
 )
 
@@ -39,8 +40,8 @@ func TestParse_variables(t *testing.T) {
 					},
 				},
 				LocalVariables: Variables{
-					"owner":        &Variable{},
-					"service_name": &Variable{},
+					"owner":        &Variable{Name: "owner"},
+					"service_name": &Variable{Name: "service_name"},
 				},
 			},
 			false, false,
@@ -103,13 +104,13 @@ func TestParse_variables(t *testing.T) {
 					},
 				},
 			},
-			true, true,
+			true, false,
 			[]packer.Build{},
 			false,
 		},
-		{"unset variable",
+		{"unset used variable",
 			defaultParser,
-			parseTestArgs{"testdata/variables/unset_string_variable.pkr.hcl", nil},
+			parseTestArgs{"testdata/variables/unset_used_string_variable.pkr.hcl", nil},
 			&PackerConfig{
 				Basedir: filepath.Join("testdata", "variables"),
 				InputVariables: Variables{
@@ -131,7 +132,40 @@ func TestParse_variables(t *testing.T) {
 			},
 			true, true,
 			[]packer.Build{},
-			true,
+			false,
+		},
+		{"unset unused variable",
+			defaultParser,
+			parseTestArgs{"testdata/variables/unset_unused_string_variable.pkr.hcl", nil},
+			&PackerConfig{
+				Basedir: filepath.Join("testdata", "variables"),
+				InputVariables: Variables{
+					"foo": &Variable{
+						Name: "foo",
+					},
+				},
+				Sources: map[SourceRef]*SourceBlock{
+					SourceRef{"null", "null-builder"}: &SourceBlock{
+						Name: "null-builder",
+						Type: "null",
+					},
+				},
+				Builds: Builds{
+					&BuildBlock{
+						Sources: []SourceRef{SourceRef{"null", "null-builder"}},
+					},
+				},
+			},
+			false, false,
+			[]packer.Build{
+				&packer.CoreBuild{
+					Type:           "null",
+					Builder:        &null.Builder{},
+					Provisioners:   []packer.CoreBuildProvisioner{},
+					PostProcessors: [][]packer.CoreBuildPostProcessor{},
+				},
+			},
+			false,
 		},
 	}
 	testParse(t, tests)