diff --git a/src/main/resources/db/migration/V4__Fix_SystemLogs_Table.sql b/src/main/resources/db/migration/V4__Fix_SystemLogs_Table.sql
index 39c331f..b0c2f37 100644
--- a/src/main/resources/db/migration/V4__Fix_SystemLogs_Table.sql
+++ b/src/main/resources/db/migration/V4__Fix_SystemLogs_Table.sql
@@ -7,9 +7,15 @@
 --              dans system_logs pour correspondre à l'entité JPA SystemLog
 -- ============================================================================
 
--- 1. Renommer les colonnes avec des noms incorrects
-ALTER TABLE system_logs RENAME COLUMN niveau TO level;
-ALTER TABLE system_logs RENAME COLUMN stacktrace TO details;
+-- 1. Renommer les colonnes avec des noms incorrects (si elles existent encore)
+DO $$ BEGIN
+    IF EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name='system_logs' AND column_name='niveau') THEN
+        ALTER TABLE system_logs RENAME COLUMN niveau TO level;
+    END IF;
+    IF EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name='system_logs' AND column_name='stacktrace') THEN
+        ALTER TABLE system_logs RENAME COLUMN stacktrace TO details;
+    END IF;
+END $$;
 
 -- 2. Modifier utilisateur_id: UUID → VARCHAR(255) et renommer user_id
 -- D'abord supprimer la colonne UUID, puis ajouter VARCHAR
diff --git a/src/main/resources/db/migration/V6__Create_Communication_Tables.sql b/src/main/resources/db/migration/V6__Create_Communication_Tables.sql
index aa2369d..a8f20d3 100644
--- a/src/main/resources/db/migration/V6__Create_Communication_Tables.sql
+++ b/src/main/resources/db/migration/V6__Create_Communication_Tables.sql
@@ -5,7 +5,7 @@
 -- ============================================================================
 
 -- Table conversations
-CREATE TABLE conversations (
+CREATE TABLE IF NOT EXISTS conversations (
     id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
     name VARCHAR(255) NOT NULL,
     description VARCHAR(1000),
@@ -31,13 +31,13 @@ CREATE TABLE conversations (
 );
 
 -- Index pour conversations
-CREATE INDEX idx_conversation_organisation ON conversations(organisation_id);
-CREATE INDEX idx_conversation_type ON conversations(type);
-CREATE INDEX idx_conversation_archived ON conversations(is_archived);
-CREATE INDEX idx_conversation_created ON conversations(date_creation);
+CREATE INDEX IF NOT EXISTS idx_conversation_organisation ON conversations(organisation_id);
+CREATE INDEX IF NOT EXISTS idx_conversation_type ON conversations(type);
+CREATE INDEX IF NOT EXISTS idx_conversation_archived ON conversations(is_archived);
+CREATE INDEX IF NOT EXISTS idx_conversation_created ON conversations(date_creation);
 
 -- Table de jointure conversation_participants (many-to-many)
-CREATE TABLE conversation_participants (
+CREATE TABLE IF NOT EXISTS conversation_participants (
     conversation_id UUID NOT NULL,
     membre_id UUID NOT NULL,
     joined_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
@@ -51,11 +51,11 @@ CREATE TABLE conversation_participants (
 );
 
 -- Index pour conversation_participants
-CREATE INDEX idx_conv_participants_membre ON conversation_participants(membre_id);
-CREATE INDEX idx_conv_participants_conversation ON conversation_participants(conversation_id);
+CREATE INDEX IF NOT EXISTS idx_conv_participants_membre ON conversation_participants(membre_id);
+CREATE INDEX IF NOT EXISTS idx_conv_participants_conversation ON conversation_participants(conversation_id);
 
 -- Table messages
-CREATE TABLE messages (
+CREATE TABLE IF NOT EXISTS messages (
     id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
     conversation_id UUID NOT NULL,
     sender_id UUID NOT NULL,
@@ -92,12 +92,12 @@ CREATE TABLE messages (
 );
 
 -- Index pour messages
-CREATE INDEX idx_message_conversation ON messages(conversation_id);
-CREATE INDEX idx_message_sender ON messages(sender_id);
-CREATE INDEX idx_message_organisation ON messages(organisation_id);
-CREATE INDEX idx_message_status ON messages(status);
-CREATE INDEX idx_message_created ON messages(date_creation);
-CREATE INDEX idx_message_deleted ON messages(is_deleted);
+CREATE INDEX IF NOT EXISTS idx_message_conversation ON messages(conversation_id);
+CREATE INDEX IF NOT EXISTS idx_message_sender ON messages(sender_id);
+CREATE INDEX IF NOT EXISTS idx_message_organisation ON messages(organisation_id);
+CREATE INDEX IF NOT EXISTS idx_message_status ON messages(status);
+CREATE INDEX IF NOT EXISTS idx_message_created ON messages(date_creation);
+CREATE INDEX IF NOT EXISTS idx_message_deleted ON messages(is_deleted);
 
 -- Commentaires
 COMMENT ON TABLE conversations IS 'Conversations (fils de discussion) du système de messagerie';