diff --git a/tools/debugedit.c b/tools/debugedit.c
index 57e3872..0e05f83 100644
--- a/tools/debugedit.c
+++ b/tools/debugedit.c
@@ -651,6 +651,13 @@ edit_dwarf2_line (DSO *dso, uint32_t off, char *comp_dir, int phase)
 	  shrank += srcptr - readptr;
 	  canonicalize_path ((char *)readptr, (char *)ptr);
 	  len = strlen ((char *)ptr) + 1;
+	  if (shrank - len == 1)
+	    {
+	      /* add extra '/' to avoid shrinking by one character */
+	      len++;
+	      ptr[len - 2] = '/';
+	      ptr[len - 1] = '\0';
+	    }
 	  shrank -= len;
 	  ptr += len;