diff --git a/src/comp.c b/src/comp.c
index 289d89d37d..980462b520 100644
--- a/src/comp.c
+++ b/src/comp.c
@@ -433,6 +433,12 @@ #define TEXT_DATA_RELOC_EPHEMERAL_SYM "text_data_reloc_eph"
 #define TEXT_OPTIM_QLY_SYM "text_optim_qly"
 #define TEXT_FDOC_SYM "text_data_fdoc"
 
+#ifdef WINDOWSNT
+#define DIR_SLASH "\\"
+#else
+#define DIR_SLASH "/"
+#endif
+
 #define STR_VALUE(s) #s
 #define STR(s) STR_VALUE (s)
 
@@ -4032,9 +4038,11 @@ DEFUN ("comp-el-to-eln-filename", Fcomp_el_to_eln_filename,
     {
       Lisp_Object sys_re =
 	concat2 (build_string ("\\`[[:ascii:]]+"),
-		 Fregexp_quote (build_string ("/" PATH_REL_LOADSEARCH "/")));
+		 Fregexp_quote (build_string (DIR_SLASH PATH_REL_LOADSEARCH
+					      DIR_SLASH)));
       loadsearch_re_list =
-	list2 (sys_re, Fregexp_quote (build_string (PATH_DUMPLOADSEARCH "/")));
+	list2 (sys_re, Fregexp_quote (build_string (PATH_DUMPLOADSEARCH
+						    DIR_SLASH)));
     }
 
   Lisp_Object lds_re_tail = loadsearch_re_list;