diff --git a/R/interactive_plots.R b/R/interactive_plots.R
index 334c844b..61246bed 100644
--- a/R/interactive_plots.R
+++ b/R/interactive_plots.R
@@ -38,6 +38,7 @@
 #' `"Portland"`, `"Rainbow"`, `"RdBu"`, `"Reds"`, `"Viridis"`, `"YlGnBu"`,
 #' `"YlOrRd"`.
 #' @param showlegend whether to show the legend passed to
+#' @param make_rel logical, whether to make the spectra relative or use the raw values
 #' @param type specification for plot type either interactive or static
 #' \code{\link[plotly]{plot_ly}()}.
 #' @param \ldots further arguments passed to \code{\link[plotly]{plot_ly}()}.
@@ -88,8 +89,9 @@ plotly_spec.OpenSpecy <- function(x,
                                   plot_bgcolor = 'rgba(17, 0, 73, 0)',
                                   paper_bgcolor = 'rgb(0, 0, 0)',
                                   showlegend = FALSE,
+                                  make_rel = TRUE,
                                   ...) {
-  x <- make_rel(x, na.rm = T)
+  if(make_rel)   x <- make_rel(x, na.rm = T)
   dt <- cbind(wavenumber = x$wavenumber, x$spectra) |>
     melt(
       id.vars = "wavenumber",
@@ -117,7 +119,7 @@ plotly_spec.OpenSpecy <- function(x,
     )
 
   if(!is.null(x2)) {
-    x2 <- make_rel(x2, na.rm = T)
+    if(make_rel) x2 <- make_rel(x2, na.rm = T)
     dt2 <- cbind(wavenumber = x2$wavenumber, x2$spectra) |>
       melt(
         id.vars = "wavenumber",
diff --git a/man/interactive_plots.Rd b/man/interactive_plots.Rd
index e05a9657..3c8832e1 100644
--- a/man/interactive_plots.Rd
+++ b/man/interactive_plots.Rd
@@ -25,6 +25,7 @@ plotly_spec(x, ...)
   plot_bgcolor = "rgba(17, 0, 73, 0)",
   paper_bgcolor = "rgb(0, 0, 0)",
   showlegend = FALSE,
+  make_rel = TRUE,
   ...
 )
 
@@ -86,6 +87,8 @@ spectral data for the second group.}
 
 \item{showlegend}{whether to show the legend passed to}
 
+\item{make_rel}{logical, whether to make the spectra relative or use the raw values}
+
 \item{z}{optional numeric vector specifying the intensity values for the
 heatmap. If not provided, the function will use the intensity values from the
 \code{OpenSpecy} object.}