diff --git a/R/ggplot-theme.R b/R/ggplot-theme.R
index 0f6aabe..aa68c42 100644
--- a/R/ggplot-theme.R
+++ b/R/ggplot-theme.R
@@ -48,9 +48,9 @@
                axis.title.x = element_text(hjust = 0.5, size=11),
                axis.title.y = element_text(hjust = 0.5, size=11),
                legend.title = element_text(size=11),
+               panel.grid.major.x = element_line(linetype = "dotted", colour = lowContrastColor),
                panel.grid.major.y = element_line(colour = lowContrastColor),
                panel.grid.minor.y = element_blank(),
-               panel.grid.major.x = element_blank(),
                panel.grid.minor.x = element_blank(),
                panel.border = element_blank(),
                panel.background = element_blank(),