diff --git a/src/interdiff.c b/src/interdiff.c
index f3f474b0..d1cc9e25 100644
--- a/src/interdiff.c
+++ b/src/interdiff.c
@@ -132,9 +132,9 @@ static struct file_list *files_in_patch1 = NULL;
 /*
  * Print colored output using a variadic format string.
  */
- static void
- print_color (FILE *output_file, enum line_type type, const char *format, ...)
- {
+static void __attribute__((__format__(printf, 3, 4)))
+print_color (FILE *output_file, enum line_type type, const char *format, ...)
+{
 	const char *color_start = NULL;
 	va_list args;
 
@@ -154,7 +154,7 @@ static struct file_list *files_in_patch1 = NULL;
 	/* Print color end code */
 	if (color_start)
 		fputs ("\033[0m", output_file);
- }
+}
 
  /* checks whether file needs processing and sets context */
 static int
@@ -1099,21 +1099,18 @@ trim_context (FILE *f /* positioned at start of @@ line */,
 			printf ("Trim: %lu,%lu\n", strip_pre, strip_post);
 
 		fsetpos (f, &pos);
-		{
-			if (new_orig_count != 1 && new_new_count != 1) {
-				print_color (out, LINE_HUNK, "@@ -%lu,%lu +%lu,%lu @@\n",
-					     orig_offset, new_orig_count, new_offset, new_new_count);
-			} else if (new_orig_count != 1) {
-				print_color (out, LINE_HUNK, "@@ -%lu,%lu +%lu @@\n",
-					     orig_offset, new_orig_count, new_offset);
-			} else if (new_new_count != 1) {
-				print_color (out, LINE_HUNK, "@@ -%lu +%lu,%lu @@\n",
-					     orig_offset, new_offset, new_new_count);
-			} else {
-				print_color (out, LINE_HUNK, "@@ -%lu +%lu @@\n",
-					     orig_offset, new_offset);
-			}
-		}
+		if (new_orig_count != 1 && new_new_count != 1)
+			print_color (out, LINE_HUNK, "@@ -%lu,%lu +%lu,%lu @@\n",
+				     orig_offset, new_orig_count, new_offset, new_new_count);
+		else if (new_orig_count != 1)
+			print_color (out, LINE_HUNK, "@@ -%lu,%lu +%lu @@\n",
+				     orig_offset, new_orig_count, new_offset);
+		else if (new_new_count != 1)
+			print_color (out, LINE_HUNK, "@@ -%lu +%lu,%lu @@\n",
+				     orig_offset, new_offset, new_new_count);
+		else
+			print_color (out, LINE_HUNK, "@@ -%lu +%lu @@\n",
+				     orig_offset, new_offset);
 
 		while (total_count--) {
 			enum line_type type;