diff --git a/ghc/compiler/basicTypes/OccName.lhs b/ghc/compiler/basicTypes/OccName.lhs
index 4a0901f703b2e6877a3a54372adcf16707bdbfd7..f17156c09b5aceab6015168a6537ccf8652d9c2f 100644
--- a/ghc/compiler/basicTypes/OccName.lhs
+++ b/ghc/compiler/basicTypes/OccName.lhs
@@ -581,7 +581,7 @@ encode_ch '#'  = "Zh"
 encode_ch '<'  = "Zl"
 encode_ch '-'  = "Zm"
 encode_ch '!'  = "Zn"
-encode_ch '.'  = "Zd"
+encode_ch '.'  = "Zs"
 encode_ch '\'' = "Zq"
 encode_ch '*'  = "Zt"
 encode_ch '+'  = "Zp"