diff --git a/hcl2template/types.hcl_post-processor.go b/hcl2template/types.hcl_post-processor.go
index b09bcd73c..249e1e7c5 100644
--- a/hcl2template/types.hcl_post-processor.go
+++ b/hcl2template/types.hcl_post-processor.go
@@ -2,7 +2,6 @@ package hcl2template
 
 import (
 	"context"
-	"fmt"
 
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/hcldec"
@@ -33,18 +32,12 @@ func (p *HCL2PostProcessor) HCL2Prepare(buildVars map[string]interface{}) error
 		ectx = p.evalContext.NewChild()
 		buildValues := map[string]cty.Value{}
 		for k, v := range buildVars {
-			switch v := v.(type) {
-			case string:
-				buildValues[k] = cty.StringVal(v)
-			case int64:
-				buildValues[k] = cty.NumberIntVal(v)
-			case uint64:
-				buildValues[k] = cty.NumberUIntVal(v)
-			case bool:
-				buildValues[k] = cty.BoolVal(v)
-			default:
-				return fmt.Errorf("unhandled buildvar type: %T", v)
+			val, err := ConvertPluginConfigValueToHCLValue(v)
+			if err != nil {
+				return err
 			}
+
+			buildValues[k] = val
 		}
 		ectx.Variables = map[string]cty.Value{
 			buildAccessor: cty.ObjectVal(buildValues),
diff --git a/hcl2template/types.hcl_provisioner.go b/hcl2template/types.hcl_provisioner.go
index c5ee23a5a..61ba775ab 100644
--- a/hcl2template/types.hcl_provisioner.go
+++ b/hcl2template/types.hcl_provisioner.go
@@ -2,7 +2,6 @@ package hcl2template
 
 import (
 	"context"
-	"fmt"
 
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/hcldec"
@@ -37,20 +36,12 @@ func (p *HCL2Provisioner) HCL2Prepare(buildVars map[string]interface{}) error {
 			buildValues = p.evalContext.Variables[buildAccessor].AsValueMap()
 		}
 		for k, v := range buildVars {
-			switch v := v.(type) {
-			case string:
-				buildValues[k] = cty.StringVal(v)
-			case uint8:
-				buildValues[k] = cty.NumberUIntVal(uint64(v))
-			case int64:
-				buildValues[k] = cty.NumberIntVal(v)
-			case uint64:
-				buildValues[k] = cty.NumberUIntVal(v)
-			case bool:
-				buildValues[k] = cty.BoolVal(v)
-			default:
-				return fmt.Errorf("unhandled buildvar type: %T", v)
+			val, err := ConvertPluginConfigValueToHCLValue(v)
+			if err != nil {
+				return err
 			}
+
+			buildValues[k] = val
 		}
 		ectx.Variables = map[string]cty.Value{
 			buildAccessor: cty.ObjectVal(buildValues),
diff --git a/hcl2template/utils.go b/hcl2template/utils.go
index 02430a86a..f27d10497 100644
--- a/hcl2template/utils.go
+++ b/hcl2template/utils.go
@@ -124,3 +124,48 @@ func PrintableCtyValue(v cty.Value) string {
 	str := repl.FormatResult(gval)
 	return str
 }
+
+func ConvertPluginConfigValueToHCLValue(v interface{}) (cty.Value, error) {
+	var buildValue cty.Value
+	switch v := v.(type) {
+	case bool:
+		buildValue = cty.BoolVal(v)
+	case string:
+		buildValue = cty.StringVal(v)
+	case uint8:
+		buildValue = cty.NumberUIntVal(uint64(v))
+	case float64:
+		buildValue = cty.NumberFloatVal(v)
+	case int64:
+		buildValue = cty.NumberIntVal(v)
+	case uint64:
+		buildValue = cty.NumberUIntVal(v)
+	case []string:
+		vals := make([]cty.Value, len(v))
+		for i, ev := range v {
+			vals[i] = cty.StringVal(ev)
+		}
+		buildValue = cty.ListVal(vals)
+	case []uint8:
+		vals := make([]cty.Value, len(v))
+		for i, ev := range v {
+			vals[i] = cty.NumberUIntVal(uint64(ev))
+		}
+		buildValue = cty.ListVal(vals)
+	case []int64:
+		vals := make([]cty.Value, len(v))
+		for i, ev := range v {
+			vals[i] = cty.NumberIntVal(ev)
+		}
+		buildValue = cty.ListVal(vals)
+	case []uint64:
+		vals := make([]cty.Value, len(v))
+		for i, ev := range v {
+			vals[i] = cty.NumberUIntVal(ev)
+		}
+		buildValue = cty.ListVal(vals)
+	default:
+		return cty.Value{}, fmt.Errorf("unhandled buildvar type: %T", v)
+	}
+	return buildValue, nil
+}