diff --git a/logback-classic-blackbox/pom.xml b/logback-classic-blackbox/pom.xml
index 41f77a6ada..019fd6ea4a 100644
--- a/logback-classic-blackbox/pom.xml
+++ b/logback-classic-blackbox/pom.xml
@@ -8,7 +8,7 @@
     <parent>
         <groupId>ch.qos.logback</groupId>
         <artifactId>logback-parent</artifactId>
-        <version>1.5.4</version>
+        <version>1.5.5-SNAPSHOT</version>
     </parent>
 
     <artifactId>logback-classic-blackbox</artifactId>
diff --git a/logback-classic/pom.xml b/logback-classic/pom.xml
index 6866d4289f..0de1eb8263 100755
--- a/logback-classic/pom.xml
+++ b/logback-classic/pom.xml
@@ -8,7 +8,7 @@
   <parent>
     <groupId>ch.qos.logback</groupId>
     <artifactId>logback-parent</artifactId>
-    <version>1.5.4</version>
+    <version>1.5.5-SNAPSHOT</version>
   </parent>
 
   <artifactId>logback-classic</artifactId>
diff --git a/logback-core-blackbox/pom.xml b/logback-core-blackbox/pom.xml
index 75eb0a7896..b0b76d2027 100644
--- a/logback-core-blackbox/pom.xml
+++ b/logback-core-blackbox/pom.xml
@@ -8,7 +8,7 @@
     <parent>
         <groupId>ch.qos.logback</groupId>
         <artifactId>logback-parent</artifactId>
-        <version>1.5.4</version>
+        <version>1.5.5-SNAPSHOT</version>
     </parent>
 
     <artifactId>logback-core-blackbox</artifactId>
diff --git a/logback-core/pom.xml b/logback-core/pom.xml
index 8816596141..99728ba6bf 100755
--- a/logback-core/pom.xml
+++ b/logback-core/pom.xml
@@ -8,7 +8,7 @@
     <parent>
         <groupId>ch.qos.logback</groupId>
         <artifactId>logback-parent</artifactId>
-        <version>1.5.4</version>
+        <version>1.5.5-SNAPSHOT</version>
     </parent>
 
     <artifactId>logback-core</artifactId>
diff --git a/logback-examples/pom.xml b/logback-examples/pom.xml
index ab6a8b1388..695b1ebab4 100755
--- a/logback-examples/pom.xml
+++ b/logback-examples/pom.xml
@@ -8,7 +8,7 @@
   <parent>
     <groupId>ch.qos.logback</groupId>
     <artifactId>logback-parent</artifactId>
-    <version>1.5.4</version>
+    <version>1.5.5-SNAPSHOT</version>
   </parent>
 
   <artifactId>logback-examples</artifactId>
diff --git a/pom.xml b/pom.xml
index fd2451bae4..d33e0b18fb 100755
--- a/pom.xml
+++ b/pom.xml
@@ -7,7 +7,7 @@
 
   <groupId>ch.qos.logback</groupId>
   <artifactId>logback-parent</artifactId>
-  <version>1.5.4</version>
+  <version>1.5.5-SNAPSHOT</version>
   <packaging>pom</packaging>
 
   <name>Logback-Parent</name>
@@ -48,7 +48,7 @@
 
   <properties>
     <!-- yyyy-MM-dd'T'HH:mm:ss'Z' -->
-    <project.build.outputTimestamp>2024-04-09T07:33:00Z</project.build.outputTimestamp>
+    <project.build.outputTimestamp>2024-04-09T08:54:44Z</project.build.outputTimestamp>
 
     <!-- minimal JDK version at runtime -->
     <jdk.version>11</jdk.version>