diff --git a/R/data.table.R b/R/data.table.R
index d0b940ae1..1c2c07a3f 100644
--- a/R/data.table.R
+++ b/R/data.table.R
@@ -123,7 +123,8 @@ replace_dot_alias = function(e) {
       stopf("Object '%s' not found amongst %s", used, brackify(ref))
     }
   } else {
-    stopf(err$message)
+    # Don't use stopf() directly, since err$message might have '%', #6588
+    stopf("%s", err$message, domain=NA)
   }
 }
 
diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index c530b2fd1..2e90de1ba 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -20591,3 +20591,6 @@ setDT(d2)
 test(2295.1, !is.data.table(d1))
 test(2295.2, rownames(d1), 'b')
 test(2295.3, is.data.table(d2))
+
+# #6588: .checkTypos used to give arbitrary strings to stopf as the first argument
+test(2296, d2[x %no such operator% 1], error = '%no such operator%')