diff --git a/src/rime/gear/script_translator.cc b/src/rime/gear/script_translator.cc
index 250616593..49cccc2dd 100644
--- a/src/rime/gear/script_translator.cc
+++ b/src/rime/gear/script_translator.cc
@@ -32,6 +32,8 @@
 
 namespace rime {
 
+using std::exp;
+
 namespace {
 
 struct SyllabifyTask {
diff --git a/src/rime/gear/table_translator.cc b/src/rime/gear/table_translator.cc
index c95e5e24b..dccaac33d 100644
--- a/src/rime/gear/table_translator.cc
+++ b/src/rime/gear/table_translator.cc
@@ -26,6 +26,8 @@
 
 namespace rime {
 
+using std::exp;
+
 static const char* kUnitySymbol = " \xe2\x98\xaf ";
 
 // TableTranslation