diff --git a/base/include/hidl/HidlSupport.h b/base/include/hidl/HidlSupport.h
index f44160f..5cda20a 100644
--- a/base/include/hidl/HidlSupport.h
+++ b/base/include/hidl/HidlSupport.h
@@ -173,15 +173,15 @@
 };
 
 // Use NOLINT to suppress missing parentheses warnings around OP.
-#define HIDL_STRING_OPERATOR(OP)                                               \
-    inline bool operator OP(const hidl_string &hs1, const hidl_string &hs2) {  \
-        return strcmp(hs1.c_str(), hs2.c_str()) OP 0;     /* NOLINT */         \
-    }                                                                          \
-    inline bool operator OP(const hidl_string &hs, const char *s) {            \
-        return strcmp(hs.c_str(), s) OP 0;                /* NOLINT */         \
-    }                                                                          \
-    inline bool operator OP(const char *s, const hidl_string &hs) {            \
-        return strcmp(hs.c_str(), s) OP 0;                /* NOLINT */         \
+#define HIDL_STRING_OPERATOR(OP)                                              \
+    inline bool operator OP(const hidl_string& hs1, const hidl_string& hs2) { \
+        return strcmp(hs1.c_str(), hs2.c_str()) OP 0; /* NOLINT */            \
+    }                                                                         \
+    inline bool operator OP(const hidl_string& hs, const char* s) {           \
+        return strcmp(hs.c_str(), s) OP 0; /* NOLINT */                       \
+    }                                                                         \
+    inline bool operator OP(const char* s, const hidl_string& hs) {           \
+        return strcmp(s, hs.c_str()) OP 0; /* NOLINT */                       \
     }
 
 HIDL_STRING_OPERATOR(==)