diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 374447f87..cb33a8d24 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -42,6 +42,11 @@ jobs:
       - name: depends
         run:  bundle install
 
+      # Enable the verbose option in mkmf.rb to print the compiling commands.
+      - name: enable mkmf verbose
+        run:  tool/enable-mkmf-verbose
+        if: runner.os == 'Linux' || runner.os == 'macOS'
+
       - name: compile
         run:  rake compile -- --enable-debug
 
@@ -129,6 +134,10 @@ jobs:
       - name: depends
         run:  bundle install
 
+      - name: enable mkmf verbose
+        run:  tool/enable-mkmf-verbose
+        if: runner.os == 'Linux' || runner.os == 'macOS'
+
       - name: compile
         run:  rake compile -- --enable-debug --with-openssl-dir=$HOME/.openssl/${{ matrix.openssl }}
 
diff --git a/tool/enable-mkmf-verbose b/tool/enable-mkmf-verbose
new file mode 100755
index 000000000..f715d4080
--- /dev/null
+++ b/tool/enable-mkmf-verbose
@@ -0,0 +1,17 @@
+#!/bin/sh -eu
+
+set -x
+
+gem_home="$(gem environment home)"
+mkmf_rb_path="$(find "${gem_home}"/../.. -name mkmf.rb)"
+
+# Backup the original file.
+cp -p "${mkmf_rb_path}" "${mkmf_rb_path}.orig"
+
+# Replace the target line to set the verbose option.
+sed -i -e 's/^V = .*/V = 1/' "${mkmf_rb_path}"
+# Check if the sed command above replaced the expected line properly.
+grep -q '^V = ' "${mkmf_rb_path}"
+
+# Print the difference between the original file and modified file.
+diff "${mkmf_rb_path}.orig" "${mkmf_rb_path}" || :