diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 43d97564c..593e99611 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -92,7 +92,7 @@ jobs:
       - name: run compiler tests
         run: |
           cd test
-          ..\build\${{ matrix.build_type }}\c3c.exe compile-run -O1 src/test_suite_runner.c3 -- ..\build\${{ matrix.build_type }}\c3c.exe test_suite/
+          ..\build\${{ matrix.build_type }}\c3c.exe compile-run -O0 src/test_suite_runner.c3 -- ..\build\${{ matrix.build_type }}\c3c.exe test_suite/
 
       - name: Compile run unit tests
         run: |
diff --git a/lib/std/threads/fixed_pool.c3 b/lib/std/threads/fixed_pool.c3
index d349f18cc..431e242ea 100644
--- a/lib/std/threads/fixed_pool.c3
+++ b/lib/std/threads/fixed_pool.c3
@@ -69,13 +69,13 @@ fn void? FixedThreadPool.join(&self) @maydiscard // Remove optional in 0.8.0
 {
 	if (self.initialized)
 	{
-		self.mu.lock()!!;
+		self.mu.lock();
 		defer self.mu.unlock();
 		self.joining = true;
 		do
 		{
-			self.notify.broadcast()!!;
-			self.collect.wait(&self.mu)!!;
+			self.notify.broadcast();
+			self.collect.wait(&self.mu);
 		} while (self.qindex != 0 || self.qworking != 0);
 		self.joining = false;
 	}
@@ -171,7 +171,7 @@ fn int process_work(void* self_arg) @private
 		// Wait for work.
 		while (self.qindex == 0)
 		{
-			if (self.joining && self.qworking == 0) self.collect.signal()!!;
+			if (self.joining && self.qworking == 0) self.collect.signal();
 			if (self.stop)
 			{
 				// Shutdown requested.
@@ -179,7 +179,7 @@ fn int process_work(void* self_arg) @private
 				self.mu.unlock();
 				return 0;
 			}
-			self.notify.wait(&self.mu)!!;
+			self.notify.wait(&self.mu);
 			if (self.stop_now)
 			{
 				// Shutdown requested.