diff --git a/.github/workflows/run_quick_tests.yaml b/.github/workflows/run_quick_tests.yaml
index 9e6a06c..91b3f15 100644
--- a/.github/workflows/run_quick_tests.yaml
+++ b/.github/workflows/run_quick_tests.yaml
@@ -34,12 +34,17 @@ jobs:
           else
             echo "BRANCH_NAME=${{ github.ref_name }}" >> $GITHUB_ENV
           fi
-          
+
+      - name: Install system dependencies
+        run: |
+          apt-get update
+          # libuv1-dev: required to compile 'fs' (>= 2.x), a transitive dep of testthat.
+          # zlib1g-dev: enables data.table fwrite compression (otherwise NOZLIB).
+          apt-get install -y libuv1-dev zlib1g-dev
+
       - name: Install R dependencies
         run: |
-          Rscript -e 'install.packages("testthat", repos="https://cran.rstudio.com/")'
-          Rscript -e 'install.packages("data.table", repos="https://cran.rstudio.com/")'
-          Rscript -e 'install.packages("R.utils", repos="https://cran.rstudio.com/")'
+          Rscript -e 'pkgs <- c("testthat", "data.table", "R.utils"); install.packages(pkgs, repos = "https://cran.rstudio.com/"); missing <- pkgs[!pkgs %in% rownames(installed.packages())]; if (length(missing)) stop("Failed to install: ", paste(missing, collapse = ", "))'
 
       - name: Run tests
         run: |
diff --git a/pipeline/rules/dependencies.smk b/pipeline/rules/dependencies.smk
index 8913566..76623ae 100644
--- a/pipeline/rules/dependencies.smk
+++ b/pipeline/rules/dependencies.smk
@@ -728,6 +728,10 @@ rule download_prscs_ref_ukb:
       rm -r -f {resdir}/data/prscs_ref/ukbb/ldblk_ukbb_{wildcards.population}; \
       wget --no-check-certificate -O {resdir}/data/prscs_ref/ukbb/ldblk_ukbb_{wildcards.population}.tar.gz {params.url}; \
       tar -zxvf {resdir}/data/prscs_ref/ukbb/ldblk_ukbb_{wildcards.population}.tar.gz -C {resdir}/data/prscs_ref/ukbb/; \
+      extracted_dir=$(tar -tzf {resdir}/data/prscs_ref/ukbb/ldblk_ukbb_{wildcards.population}.tar.gz | head -1 | cut -d/ -f1); \
+      if [ "$extracted_dir" != "ldblk_ukbb_{wildcards.population}" ]; then \
+        mv {resdir}/data/prscs_ref/ukbb/"$extracted_dir" {resdir}/data/prscs_ref/ukbb/ldblk_ukbb_{wildcards.population}; \
+      fi; \
       rm {resdir}/data/prscs_ref/ukbb/ldblk_ukbb_{wildcards.population}.tar.gz
     }} > {log} 2>&1
     """
@@ -761,6 +765,10 @@ rule download_prscs_ref_1kg:
       rm -r -f {resdir}/data/prscs_ref/1kg/ldblk_1kg_{wildcards.population}; \
       wget --no-check-certificate -O {resdir}/data/prscs_ref/1kg/ldblk_1kg_{wildcards.population}.tar.gz {params.url}; \
       tar -zxvf {resdir}/data/prscs_ref/1kg/ldblk_1kg_{wildcards.population}.tar.gz -C {resdir}/data/prscs_ref/1kg/; \
+      extracted_dir=$(tar -tzf {resdir}/data/prscs_ref/1kg/ldblk_1kg_{wildcards.population}.tar.gz | head -1 | cut -d/ -f1); \
+      if [ "$extracted_dir" != "ldblk_1kg_{wildcards.population}" ]; then \
+        mv {resdir}/data/prscs_ref/1kg/"$extracted_dir" {resdir}/data/prscs_ref/1kg/ldblk_1kg_{wildcards.population}; \
+      fi; \
       rm {resdir}/data/prscs_ref/1kg/ldblk_1kg_{wildcards.population}.tar.gz
     }} > {log} 2>&1
     """