diff --git a/R/guide-bins.R b/R/guide-bins.R
index e2bd0db428..d1856a69ed 100644
--- a/R/guide-bins.R
+++ b/R/guide-bins.R
@@ -154,7 +154,7 @@ GuideBins <- ggproto(
     key$.show  <- NA
 
     labels <- scale$get_labels(breaks)
-    if (is.character(scale$labels) || is.numeric(scale$labels)) {
+    if (is.character(scale$labels) || is.numeric(scale$labels) || is.expression(scale$labels)) {
       limit_lab <- c(NA, NA)
     } else {
       limit_lab <- scale$get_labels(limits)
@@ -169,6 +169,9 @@ GuideBins <- ggproto(
     } else {
       key$.show[nrow(key)] <- TRUE
     }
+    if (is.expression(labels)) {
+      labels <- as.list(labels)
+    }
 
     key$.label <- labels
     key <- vec_slice(key, !is.na(oob_censor_any(key$.value)))
@@ -258,7 +261,7 @@ GuideBins <- ggproto(
 
     list(labels = flip_element_grob(
       elements$text,
-      label = key$.label,
+      label = validate_labels(key$.label),
       x = unit(key$.value, "npc"),
       margin_x = FALSE,
       margin_y = TRUE,
diff --git a/R/guide-colorsteps.R b/R/guide-colorsteps.R
index 52b6e1809d..2df02cd972 100644
--- a/R/guide-colorsteps.R
+++ b/R/guide-colorsteps.R
@@ -114,7 +114,11 @@ GuideColoursteps <- ggproto(
     } else {
       key$.value <- breaks
     }
-    key$.label <- scale$get_labels(breaks)
+    labels <- scale$get_labels(breaks)
+    if (is.expression(labels)) {
+      labels <- as.list(labels)
+    }
+    key$.label <- labels
 
     if (breaks[1] %in% limits) {
       key$.value  <- key$.value - 1L