diff --git a/aws/protocol/query/object.go b/aws/protocol/query/object.go
index 455b92515ca..261a2724f73 100644
--- a/aws/protocol/query/object.go
+++ b/aws/protocol/query/object.go
@@ -1,9 +1,6 @@
 package query
 
-import (
-	"fmt"
-	"net/url"
-)
+import "net/url"
 
 // Object represents the encoding of Query structures and unions. A Query
 // object is a representation of a mapping of string keys to arbitrary
@@ -56,14 +53,14 @@ func (o *Object) FlatKey(name string) Value {
 
 func (o *Object) key(name string, flatValue bool) Value {
 	if o.prefix != "" {
-		return newValue(o.values, fmt.Sprintf("%s.%s", o.prefix, name), flatValue)
+		return newValue(o.values, o.prefix+keySeparator+name, flatValue)
 	}
 	return newValue(o.values, name, flatValue)
 }
 
 func (o *Object) keyWithValues(name string, flatValue bool) Value {
 	if o.prefix != "" {
-		return newAppendValue(o.values, fmt.Sprintf("%s.%s", o.prefix, name), flatValue)
+		return newAppendValue(o.values, o.prefix+keySeparator+name, flatValue)
 	}
 	return newAppendValue(o.values, name, flatValue)
 }
diff --git a/aws/protocol/query/value.go b/aws/protocol/query/value.go
index a9251521f12..8063c592ddd 100644
--- a/aws/protocol/query/value.go
+++ b/aws/protocol/query/value.go
@@ -7,6 +7,8 @@ import (
 	"github.com/aws/smithy-go/encoding/httpbinding"
 )
 
+const keySeparator = "."
+
 // Value represents a Query Value type.
 type Value struct {
 	// The query values to add the value to.
diff --git a/aws/protocol/query/value_test.go b/aws/protocol/query/value_test.go
new file mode 100644
index 00000000000..f8336f39d46
--- /dev/null
+++ b/aws/protocol/query/value_test.go
@@ -0,0 +1,64 @@
+package query
+
+import (
+	"fmt"
+	"strconv"
+	"testing"
+)
+
+var output string
+
+func Benchmark_sprintf_strings(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		output = fmt.Sprintf("%s.%s", "foo", "bar")
+	}
+}
+
+func Benchmark_concat_strings(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		output = "foo" + keySeparator + "bar"
+	}
+}
+
+func Benchmark_int_formatting(b *testing.B) {
+	benchmarkFuncs := []struct {
+		name      string
+		formatter func(val int32)
+	}{
+		{
+			name: "array - sprintf", formatter: func(val int32) {
+				output = fmt.Sprintf("%s.%d", "foo", val)
+			},
+		},
+		{
+			name: "array - concat strconv", formatter: func(val int32) {
+				output = "foo" + keySeparator + strconv.FormatInt(int64(val), 10)
+			},
+		},
+		{
+			name: "map - sprintf", formatter: func(val int32) {
+				output = fmt.Sprintf("%s.%d.%s", "foo", val, "bar")
+				output = fmt.Sprintf("%s.%d.%s", "foo", val, "bar")
+			},
+		},
+		{
+			name: "map - concat strconv", formatter: func(val int32) {
+				valString := strconv.FormatInt(int64(val), 10)
+				output = "foo" + keySeparator + valString + keySeparator + "bar"
+				output = "foo" + keySeparator + valString + keySeparator + "bar"
+			},
+		},
+	}
+
+	sizesToTest := []int32{1, 10, 100, 250, 500, 1000}
+
+	for _, bm := range benchmarkFuncs {
+		for _, size := range sizesToTest {
+			b.Run(fmt.Sprintf("%s with %d size", bm.name, size), func(b *testing.B) {
+				for i := 0; i < b.N; i++ {
+					bm.formatter(size)
+				}
+			})
+		}
+	}
+}