diff --git a/.github/workflows/test-coverage.yaml b/.github/workflows/test-coverage.yaml
index 0c551839..f13105a1 100644
--- a/.github/workflows/test-coverage.yaml
+++ b/.github/workflows/test-coverage.yaml
@@ -56,7 +56,7 @@ jobs:
         shell: Rscript {0}
 
       - name: Cache R packages
-        uses: actions/cache@v1
+        uses: actions/cache@v3
         with:
           path: ${{ env.R_LIBS_USER }}
           key: macOS-r-4.0-1-${{ hashFiles('.github/depends.Rds') }}
diff --git a/R/misc_theme_drwhy.R b/R/misc_theme_drwhy.R
index f19c608d..6465a121 100644
--- a/R/misc_theme_drwhy.R
+++ b/R/misc_theme_drwhy.R
@@ -18,8 +18,8 @@ theme_drwhy <- function() {
           plot.subtitle = element_text(color = "#371ea3", hjust = 0),
           axis.text = element_text(color = "#371ea3", size = 10),
           strip.text = element_text(color = "#371ea3", size = 12, hjust = 0),
-          panel.grid.major.y = element_line(color = "grey90", size = 0.5, linetype = 1),
-          panel.grid.minor.y = element_line(color = "grey90", size = 0.5,  linetype = 1),
+          panel.grid.major.y = element_line(color = "grey90", linewidth = 0.5, linetype = 1),
+          panel.grid.minor.y = element_line(color = "grey90", linewidth = 0.5,  linetype = 1),
           panel.grid.minor.x = element_blank(),
           panel.grid.major.x = element_blank())
 
@@ -58,8 +58,8 @@ theme_drwhy_vertical <- function() {
           axis.title = element_text(color = "#371ea3"),
           axis.text = element_text(color = "#371ea3", size = 10),
           strip.text = element_text(color = "#371ea3", size = 12, hjust = 0),
-          panel.grid.major.x = element_line(color = "grey90", size = 0.5, linetype = 1),
-          panel.grid.minor.x = element_line(color = "grey90", size = 0.5,  linetype = 1),
+          panel.grid.major.x = element_line(color = "grey90", linewidth = 0.5, linetype = 1),
+          panel.grid.minor.x = element_line(color = "grey90", linewidth = 0.5,  linetype = 1),
           panel.grid.minor.y = element_blank(),
           panel.grid.major.y = element_blank())
 }
diff --git a/R/plot_model_diagnostics.R b/R/plot_model_diagnostics.R
index b9e8d01f..587277a2 100644
--- a/R/plot_model_diagnostics.R
+++ b/R/plot_model_diagnostics.R
@@ -48,7 +48,7 @@ plot.model_diagnostics <- function(x, ..., variable = "y_hat", yvariable = "resi
 
    # add hline
    if (yvariable == "residuals")
-     pl <- pl + geom_hline(yintercept = 0, color = "grey", lty = 2, size = 1)
+     pl <- pl + geom_hline(yintercept = 0, color = "grey", lty = 2, linewidth = 1)
 
     pl + ggtitle("Model diagnostics", paste0(variable, " against ", yvariable))
 }