diff --git a/spring-jdbc/src/main/java/org/springframework/jdbc/core/BeanPropertyRowMapper.java b/spring-jdbc/src/main/java/org/springframework/jdbc/core/BeanPropertyRowMapper.java
index 5a5ece73d2cd..bfc95dfaa9bf 100644
--- a/spring-jdbc/src/main/java/org/springframework/jdbc/core/BeanPropertyRowMapper.java
+++ b/spring-jdbc/src/main/java/org/springframework/jdbc/core/BeanPropertyRowMapper.java
@@ -247,16 +247,15 @@ protected String underscoreName(String name) {
 		if (!StringUtils.hasLength(name)) {
 			return "";
 		}
+
 		StringBuilder result = new StringBuilder();
-		result.append(lowerCaseName(name.substring(0, 1)));
-		for (int i = 1; i < name.length(); i++) {
-			String s = name.substring(i, i + 1);
-			String slc = lowerCaseName(s);
-			if (!s.equals(slc)) {
-				result.append("_").append(slc);
+		for (int i = 0; i < name.length(); i++) {
+			char s = name.charAt(i);
+			if (Character.isUpperCase(s)) {
+				result.append('_').append(Character.toLowerCase(s));
 			}
 			else {
-				result.append(s);
+				result.append(Character.toLowerCase(s));
 			}
 		}
 		return result.toString();