diff --git a/Source/WTF/wtf/RunLoop.h b/Source/WTF/wtf/RunLoop.h
index ab69d5d2a9fdc..9f5ff8a3cd1d1 100644
--- a/Source/WTF/wtf/RunLoop.h
+++ b/Source/WTF/wtf/RunLoop.h
@@ -144,6 +144,9 @@ class WTF_CAPABILITY("is current") RunLoop final : public GuaranteedSerialFuncti
 #if USE(GLIB_EVENT_LOOP)
         WTF_EXPORT_PRIVATE void setName(ASCIILiteral);
         WTF_EXPORT_PRIVATE void setPriority(int);
+#elif USE(BUN_EVENT_LOOP)
+        // WTFTimer in Timer.zig
+        struct Bun__WTFTimer;
 #endif
 
     private:
@@ -172,6 +175,7 @@ class WTF_CAPABILITY("is current") RunLoop final : public GuaranteedSerialFuncti
         class ScheduledTask;
         Ref<ScheduledTask> m_scheduledTask;
 #elif USE(BUN_EVENT_LOOP)
+        Bun__WTFTimer* m_zigTimer;
 #endif
     };
 
diff --git a/Source/WTF/wtf/bun/RunLoopBun.cpp b/Source/WTF/wtf/bun/RunLoopBun.cpp
index 2a61b09608fa1..2f7387715cc90 100644
--- a/Source/WTF/wtf/bun/RunLoopBun.cpp
+++ b/Source/WTF/wtf/bun/RunLoopBun.cpp
@@ -1,24 +1,66 @@
 #include "config.h"
 #include <wtf/RunLoop.h>
 
+
 namespace WTF {
 
+// Functions exported by Timer.zig
+extern "C" __attribute__((weak)) RunLoop::TimerBase::Bun__WTFTimer* WTFTimer__create(RunLoop::TimerBase*);
+extern "C" __attribute__((weak)) void WTFTimer__update(RunLoop::TimerBase::Bun__WTFTimer*, double seconds, bool repeat);
+extern "C" __attribute__((weak)) void WTFTimer__deinit(RunLoop::TimerBase::Bun__WTFTimer*);
+extern "C" __attribute__((weak)) bool WTFTimer__isActive(const RunLoop::TimerBase::Bun__WTFTimer*);
+extern "C" __attribute__((weak)) double WTFTimer__secondsUntilTimer(const RunLoop::TimerBase::Bun__WTFTimer*);
+extern "C" __attribute__((weak)) void WTFTimer__cancel(RunLoop::TimerBase::Bun__WTFTimer*);
+
 RunLoop::TimerBase::TimerBase(Ref<RunLoop>&& loop)
     : m_runLoop(WTFMove(loop))
+    // check if the zig function is actually available (it won't be in JSC shell, since that doesn't
+    // link Bun's zig code)
+    , m_zigTimer(&WTFTimer__create ? WTFTimer__create(this) : nullptr)
 {
 }
 
 RunLoop::TimerBase::~TimerBase()
 {
+    if (&WTFTimer__deinit) {
+        ASSERT(m_zigTimer);
+        WTFTimer__deinit(m_zigTimer);
+    }
 }
 
-void RunLoop::TimerBase::stop() {}
+void RunLoop::TimerBase::stop() {
+    if (&WTFTimer__cancel) {
+        ASSERT(m_zigTimer);
+        WTFTimer__cancel(m_zigTimer);
+    }
+}
 
-bool RunLoop::TimerBase::isActive() const {}
+bool RunLoop::TimerBase::isActive() const {
+    if (&WTFTimer__isActive) {
+        ASSERT(m_zigTimer);
+        return WTFTimer__isActive(m_zigTimer);
+    }
+    return false;
+}
 
-Seconds RunLoop::TimerBase::secondsUntilFire() const {}
+Seconds RunLoop::TimerBase::secondsUntilFire() const {
+    if (&WTFTimer__secondsUntilTimer) {
+        ASSERT(m_zigTimer);
+        return Seconds(WTFTimer__secondsUntilTimer(m_zigTimer));
+    }
+    return -1.0_s;
+}
+
+void RunLoop::TimerBase::start(Seconds interval, bool repeat) {
+    if (&WTFTimer__update) {
+        ASSERT(m_zigTimer);
+        WTFTimer__update(m_zigTimer, interval.value(), repeat);
+    }
+}
 
-void RunLoop::TimerBase::start(Seconds interval, bool repeat) {}
+extern "C" void WTFTimer__fire(RunLoop::TimerBase* timer) {
+    timer->fired();
+}
 
 // probably more Bun-specific TimerBase methods
 
@@ -26,14 +68,26 @@ RunLoop::RunLoop()
 {
 }
 
-RunLoop::~RunLoop() {}
+RunLoop::~RunLoop()
+{
+}
 
-void RunLoop::run() {}
+void RunLoop::run() {
+    ASSERT_NOT_REACHED();
+}
 
-void RunLoop::stop() {}
+void RunLoop::stop() {
+    ASSERT_NOT_REACHED();
+}
 
-void RunLoop::wakeUp() {}
+void RunLoop::wakeUp() {
+    ASSERT_NOT_REACHED();
+}
 
-RunLoop::CycleResult RunLoop::cycle(RunLoopMode mode) {}
+RunLoop::CycleResult RunLoop::cycle(RunLoopMode mode) {
+    (void) mode;
+    ASSERT_NOT_REACHED();
+    return RunLoop::CycleResult::Stop;
+}
 
 } // namespace WTF
diff --git a/Source/cmake/WebKitCompilerFlags.cmake b/Source/cmake/WebKitCompilerFlags.cmake
index 0307c68e5fc43..e8b26d2ebf9a4 100644
--- a/Source/cmake/WebKitCompilerFlags.cmake
+++ b/Source/cmake/WebKitCompilerFlags.cmake
@@ -228,6 +228,15 @@ if (COMPILER_IS_GCC_OR_CLANG)
     # Makes builds faster. The GCC manual warns about the possibility that the assembler being
     # used may not support input from a pipe, but in practice the toolchains we support all do.
     WEBKIT_PREPEND_GLOBAL_COMPILER_FLAGS(-pipe)
+
+    if (USE_BUN_JSC_ADDITIONS)
+        WEBKIT_PREPEND_GLOBAL_COMPILER_FLAGS(-Wl,-U,_WTFTimer__create
+                                             -Wl,-U,_WTFTimer__update
+                                             -Wl,-U,_WTFTimer__deinit
+                                             -Wl,-U,_WTFTimer__isActive
+                                             -Wl,-U,_WTFTimer__secondsUntilTimer
+                                             -Wl,-U,_WTFTimer__cancel)
+    endif ()
 endif ()
 
 if (COMPILER_IS_GCC_OR_CLANG AND NOT MSVC)