diff --git a/src/main/java/com/googlesource/gerrit/plugins/deleteproject/database/DatabaseDeleteHandler.java b/src/main/java/com/googlesource/gerrit/plugins/deleteproject/database/DatabaseDeleteHandler.java
index 7090e9b..11e146e 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/deleteproject/database/DatabaseDeleteHandler.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/deleteproject/database/DatabaseDeleteHandler.java
@@ -158,7 +158,7 @@
       try {
         indexer.delete(id);
       } catch (IOException e) {
-        log.error(String.format("Failed to delete change %s from index", id), e);
+        log.error("Failed to delete change {} from index", id, e);
       }
     }
   }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/deleteproject/fs/FilesystemDeleteHandler.java b/src/main/java/com/googlesource/gerrit/plugins/deleteproject/fs/FilesystemDeleteHandler.java
index 8aac2c1..c36ce1a 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/deleteproject/fs/FilesystemDeleteHandler.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/deleteproject/fs/FilesystemDeleteHandler.java
@@ -104,7 +104,7 @@
     } catch (IOException e) {
       // Only log if delete failed - repo already moved to trash.
       // Otherwise, listeners are never called.
-      log.warn("Error trying to delete " + trash, e);
+      log.warn("Error trying to delete {}", trash, e);
     }
 
     // Delete parent folders if they are (now) empty
@@ -112,7 +112,7 @@
       try {
         recursiveDeleteParent(repoFile.getParentFile(), basePath.toFile());
       } catch (IOException e) {
-        log.warn("Couldn't delete (empty) parents of " + repoFile, e);
+        log.warn("Couldn't delete (empty) parents of {}", repoFile, e);
       }
     }