diff --git a/instrumentation/jdbc/library/src/main/java/io/opentelemetry/instrumentation/jdbc/internal/JdbcConnectionUrlParser.java b/instrumentation/jdbc/library/src/main/java/io/opentelemetry/instrumentation/jdbc/internal/JdbcConnectionUrlParser.java
index e2f986b7f2..22d8bcdd1a 100644
--- a/instrumentation/jdbc/library/src/main/java/io/opentelemetry/instrumentation/jdbc/internal/JdbcConnectionUrlParser.java
+++ b/instrumentation/jdbc/library/src/main/java/io/opentelemetry/instrumentation/jdbc/internal/JdbcConnectionUrlParser.java
@@ -322,7 +322,7 @@ public enum JdbcConnectionUrlParser {
       int clusterSepLoc = jdbcUrl.indexOf(",");
       int ipv6End = jdbcUrl.startsWith("[") ? jdbcUrl.indexOf("]") : -1;
       int portLoc = jdbcUrl.indexOf(":", Math.max(0, ipv6End));
-      portLoc = clusterSepLoc < portLoc ? -1 : portLoc;
+      portLoc = clusterSepLoc != -1 && clusterSepLoc < portLoc ? -1 : portLoc;
       int dbLoc = jdbcUrl.indexOf("/", Math.max(portLoc, clusterSepLoc));
 
       int paramLoc = jdbcUrl.indexOf("?", dbLoc);
diff --git a/instrumentation/jdbc/library/src/test/groovy/io/opentelemetry/instrumentation/jdbc/internal/JdbcConnectionUrlParserTest.groovy b/instrumentation/jdbc/library/src/test/groovy/io/opentelemetry/instrumentation/jdbc/internal/JdbcConnectionUrlParserTest.groovy
index e6cba30668..03c6ff9c45 100644
--- a/instrumentation/jdbc/library/src/test/groovy/io/opentelemetry/instrumentation/jdbc/internal/JdbcConnectionUrlParserTest.groovy
+++ b/instrumentation/jdbc/library/src/test/groovy/io/opentelemetry/instrumentation/jdbc/internal/JdbcConnectionUrlParserTest.groovy
@@ -89,6 +89,7 @@ class JdbcConnectionUrlParserTest extends Specification {
     "jdbc:mariadb:failover://mdb.host1:33,mdb.host/mdbdb?characterEncoding=utf8"                      | null     | "mariadb:failover://mdb.host1:33"                                  | "mariadb"    | "failover"    | null          | "mdb.host1"                                 | 33    | null                               | "mdbdb"
     "jdbc:mariadb:sequential://mdb.host1,mdb.host2:33/mdbdb"                                          | null     | "mariadb:sequential://mdb.host1:3306"                              | "mariadb"    | "sequential"  | null          | "mdb.host1"                                 | 3306  | null                               | "mdbdb"
     "jdbc:mariadb:loadbalance://127.0.0.1:33,mdb.host/mdbdb"                                          | null     | "mariadb:loadbalance://127.0.0.1:33"                               | "mariadb"    | "loadbalance" | null          | "127.0.0.1"                                 | 33    | null                               | "mdbdb"
+    "jdbc:mariadb:loadbalance://127.0.0.1:33/mdbdb"                                                   | null     | "mariadb:loadbalance://127.0.0.1:33"                               | "mariadb"    | "loadbalance" | null          | "127.0.0.1"                                 | 33    | null                               | "mdbdb"
     "jdbc:mariadb:loadbalance://[2001:0660:7401:0200:0000:0000:0edf:bdd7]:33,mdb.host/mdbdb"          | null     | "mariadb:loadbalance://2001:0660:7401:0200:0000:0000:0edf:bdd7:33" | "mariadb"    | "loadbalance" | null          | "2001:0660:7401:0200:0000:0000:0edf:bdd7"   | 33    | null                               | "mdbdb"
     "jdbc:mysql:loadbalance://127.0.0.1,127.0.0.1:3306/mdbdb?user=mdbuser&password=PW"                | null     | "mysql:loadbalance://127.0.0.1:3306"                               | "mysql"      | "loadbalance" | "mdbuser"     | "127.0.0.1"                                 | 3306  | null                               | "mdbdb"
     "jdbc:mariadb:replication://localhost:33,anotherhost:3306/mdbdb"                                  | null     | "mariadb:replication://localhost:33"                               | "mariadb"    | "replication" | null          | "localhost"                                 | 33    | null                               | "mdbdb"