diff --git a/api/client/lib/image_build.go b/api/client/lib/image_build.go
index ffe8b42282..364a921fbb 100644
--- a/api/client/lib/image_build.go
+++ b/api/client/lib/image_build.go
@@ -7,6 +7,7 @@ import (
 	"net/url"
 	"regexp"
 	"strconv"
+	"strings"
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/runconfig"
@@ -101,7 +102,7 @@ func imageBuildOptionsToQuery(options types.ImageBuildOptions) (url.Values, erro
 	}
 	query.Set("ulimits", string(ulimitsJSON))
 
-	buildArgs := runconfig.ConvertKVStringsToMap(options.BuildArgs)
+	buildArgs := convertKVStringsToMap(options.BuildArgs)
 	buildArgsJSON, err := json.Marshal(buildArgs)
 	if err != nil {
 		return query, err
@@ -119,3 +120,18 @@ func getDockerOS(serverHeader string) string {
 	}
 	return osType
 }
+
+// convertKVStringsToMap converts ["key=value"] to {"key":"value"}
+func convertKVStringsToMap(values []string) map[string]string {
+	result := make(map[string]string, len(values))
+	for _, value := range values {
+		kv := strings.SplitN(value, "=", 2)
+		if len(kv) == 1 {
+			result[kv[0]] = ""
+		} else {
+			result[kv[0]] = kv[1]
+		}
+	}
+
+	return result
+}