diff --git a/blueprintcompiler/formatter.py b/blueprintcompiler/formatter.py
index 60d87b4..f438675 100644
--- a/blueprintcompiler/formatter.py
+++ b/blueprintcompiler/formatter.py
@@ -193,6 +193,9 @@ def format(data, tab_size=2, insert_space=True):
                 elif prev_line_type in require_extra_newline:
                     newlines = 2
 
+                current_line = "\n".join(
+                    [line.rstrip() for line in current_line.split("\n")]
+                )
                 commit_current_line(LineType.COMMENT, newlines_before=newlines)
 
             else:  # pragma: no cover
diff --git a/tests/formatting/comment_in.blp b/tests/formatting/comment_in.blp
index 32a907c..88b825a 100644
--- a/tests/formatting/comment_in.blp
+++ b/tests/formatting/comment_in.blp
@@ -1,2 +1,4 @@
 using Gtk 4.0;
-//comment
\ No newline at end of file
+//comment
+// Trailing whitespace:
+//       
diff --git a/tests/formatting/comment_out.blp b/tests/formatting/comment_out.blp
index d5dca95..91e647a 100644
--- a/tests/formatting/comment_out.blp
+++ b/tests/formatting/comment_out.blp
@@ -1,2 +1,4 @@
 using Gtk 4.0;
 // comment
+// Trailing whitespace:
+//