diff --git a/altdoc/altdoc_preprocessing.R b/altdoc/altdoc_preprocessing.R
index f25d21963..7ba52dc72 100644
--- a/altdoc/altdoc_preprocessing.R
+++ b/altdoc/altdoc_preprocessing.R
@@ -80,6 +80,25 @@ hierarchy = append(list("Reference" = "reference_home.md"), hierarchy)
 # Insert the links in the settings
 yml$nav[[3]]$Reference = hierarchy
 
+
+# Customize the search
+plugins = yml$plugins
+replacement = list(
+  separator = paste0("[\\s\\-\\$]+|(", paste(classes, collapse = "_|"), "_)")
+)
+if (is.character(plugins)) {
+  plugins = setNames(as.list(plugins), plugins)
+  plugins[["search"]] = replacement
+} else if (is.list(plugins)) {
+  for (i in seq_along(plugins)) {
+    if (plugins[[i]] == "search") {
+      plugins[[i]] = list(search = replacement)
+    }
+  }
+}
+yml$plugins = plugins
+
+
 # These two elements should be lists in the yaml format, not single elements,
 # otherwise mkdocs breaks
 for (i in c("extra_css", "plugins")) {