diff --git a/library/core/tests/num/dec2flt/mod.rs b/library/core/tests/num/dec2flt/mod.rs
index 0c01ee1b915ec..6fabf40717f18 100644
--- a/library/core/tests/num/dec2flt/mod.rs
+++ b/library/core/tests/num/dec2flt/mod.rs
@@ -5,6 +5,7 @@ mod decimal_seq;
 mod float;
 mod lemire;
 mod parse;
+mod slow;
 
 // Take a float literal, turn it into a string in various ways (that are all trusted
 // to be correct) and see if those strings are parsed back to the value of the literal.