diff --git a/.github/workflows/cmake-multi-platform.yml b/.github/workflows/cmake-multi-platform.yml
index a4f0dc2..010421e 100644
--- a/.github/workflows/cmake-multi-platform.yml
+++ b/.github/workflows/cmake-multi-platform.yml
@@ -77,9 +77,9 @@ jobs:
     - name: Test
       working-directory: ${{ steps.strings.outputs.build-output-dir }}
       if: runner.os != 'Windows'
-      run: sqnice_tests
+      run: ./sqnice_tests
 
     - name: Test
       working-directory: ${{ steps.strings.outputs.build-output-dir }}
       if: runner.os == 'Windows'
-      run: sqnice_tests.exe
+      run: Release/sqnice_tests.exe
diff --git a/include/sqnice/pool.hh b/include/sqnice/pool.hh
index a3b1067..35013b8 100644
--- a/include/sqnice/pool.hh
+++ b/include/sqnice/pool.hh
@@ -28,6 +28,7 @@
 #define SQNICE_POOL_H
 
 #include "sqnice/database.hh"
+#include <condition_variable>
 #include <functional>
 #include <mutex>
 #include <stack>
@@ -113,17 +114,20 @@ namespace sqnice {
         /// (The pool can still re-open more databases on demand, up to its capacity.)
         void close_unused();
 
+#ifndef __GNUC__
     private:
         friend borrowed_database;
         friend borrowed_writeable_database;
+#endif
+        void operator() (database* _Nullable) noexcept;       // deleter
+        void operator() (database const* _Nullable) noexcept; // deleter
 
+    private:
         pool(pool&&) = delete;
         pool& operator=(pool&&) = delete;
         borrowed_database borrow(bool);
         borrowed_writeable_database borrow_writeable(bool);
         std::unique_ptr<database> new_db(bool writeable);
-        void operator() (database* _Nullable) noexcept;       // deleter
-        void operator() (database const* _Nullable) noexcept; // deleter
 
         using db_ptr = std::unique_ptr<const database>;
 
diff --git a/test/testdb.cc b/test/testdb.cc
index a949412..9fb1ffd 100644
--- a/test/testdb.cc
+++ b/test/testdb.cc
@@ -151,7 +151,7 @@ TEST_CASE_METHOD(sqnice_test, "SQNice callbacks", "[sqnice]") {
 }
 
 TEST_CASE("SQNice pool", "[sqnice]") {
-    sqnice::pool p("/tmp/sqnice_test.sqlite3",
+    sqnice::pool p("sqnice_test.sqlite3",
                    sqnice::open_flags::delete_first | sqnice::open_flags::readwrite);
     {
         auto db = p.borrow_writeable();