diff --git a/headers/private/kernel/user_debugger.h b/headers/private/kernel/user_debugger.h
index dc95f36edf..43d5e9d977 100644
--- a/headers/private/kernel/user_debugger.h
+++ b/headers/private/kernel/user_debugger.h
@@ -154,17 +154,18 @@ enum {
 
 // thread debugging flags (user-specifiable flags are in <debugger.h>)
 enum {
-	B_THREAD_DEBUG_INITIALIZED		= 0x0001,
-	B_THREAD_DEBUG_DYING			= 0x0002,
-	B_THREAD_DEBUG_STOP				= 0x0004,
-	B_THREAD_DEBUG_STOPPED			= 0x0008,
-	B_THREAD_DEBUG_SINGLE_STEP		= 0x0010,
+	B_THREAD_DEBUG_INITIALIZED			= 0x0001,
+	B_THREAD_DEBUG_DYING				= 0x0002,
+	B_THREAD_DEBUG_STOP					= 0x0004,
+	B_THREAD_DEBUG_STOPPED				= 0x0008,
+	B_THREAD_DEBUG_SINGLE_STEP			= 0x0010,
+	B_THREAD_DEBUG_NOTIFY_SINGLE_STEP	= 0x0020,
 
-	B_THREAD_DEBUG_NUB_THREAD		= 0x0020,	// marks the nub thread
+	B_THREAD_DEBUG_NUB_THREAD			= 0x0040,	// marks the nub thread
 
-	B_THREAD_DEBUG_KERNEL_FLAG_MASK	= 0xffff,
+	B_THREAD_DEBUG_KERNEL_FLAG_MASK		= 0xffff,
 
-	B_THREAD_DEBUG_DEFAULT_FLAGS	= 0,
+	B_THREAD_DEBUG_DEFAULT_FLAGS		= 0,
 };
 
 // messages sent from the debug nub thread to a debugged thread
diff --git a/src/system/kernel/arch/x86/arch_user_debugger.cpp b/src/system/kernel/arch/x86/arch_user_debugger.cpp
index f8dc9fa7b0..2c784069a4 100644
--- a/src/system/kernel/arch/x86/arch_user_debugger.cpp
+++ b/src/system/kernel/arch/x86/arch_user_debugger.cpp
@@ -886,7 +886,42 @@ x86_handle_debug_exception(struct iframe *frame)
 			// it, but we don't want it when continuing otherwise.
 			frame->flags &= ~(1 << X86_EFLAGS_TF);
 
-			panic("kernel single step");
+			// Determine whether the exception occurred at a syscall/trap
+			// kernel entry or whether this is genuine kernel single-stepping.
+			bool inKernel = true;
+			struct thread* thread = thread_get_current_thread();
+			if (thread->team != team_get_kernel_team()
+				&& i386_get_user_iframe() == NULL) {
+				// TODO: This is not yet fully correct, since a newly created
+				// thread that doesn't have entered userland yet also has this
+				// property.
+				inKernel = false;
+			}
+
+			if (inKernel) {
+				panic("kernel single step");
+			} else {
+				// The thread is a userland thread and it just entered the
+				// kernel when the single-step exception occurred. This happens
+				// e.g. when sysenter is called with single-stepping enabled.
+				// We need to ignore the exception now and send a single-step
+				// notification later, when the thread wants to return from the
+				// kernel.
+				InterruptsSpinLocker threadLocker(gThreadSpinlock);
+
+				// Check whether the team is still being debugged and set
+				// the B_THREAD_DEBUG_NOTIFY_SINGLE_STEP and
+				// B_THREAD_DEBUG_STOP flags, so that the thread will be
+				// stopped when it is going to leave the kernel and notify the
+				// debugger about the single-step event.
+				int32 teamDebugFlags
+					= atomic_get(&thread->team->debug_info.flags);
+				if (teamDebugFlags & B_TEAM_DEBUG_DEBUGGER_INSTALLED) {
+					atomic_or(&thread->debug_info.flags,
+						B_THREAD_DEBUG_NOTIFY_SINGLE_STEP
+							| B_THREAD_DEBUG_STOP);
+				}
+			}
 		}
 	} else if (dr6 & (1 << X86_DR6_BT)) {
 		// task switch
diff --git a/src/system/kernel/debug/user_debugger.cpp b/src/system/kernel/debug/user_debugger.cpp
index 26fc94dacc..f77693a71e 100644
--- a/src/system/kernel/debug/user_debugger.cpp
+++ b/src/system/kernel/debug/user_debugger.cpp
@@ -954,11 +954,25 @@ user_debug_handle_signal(int signal, struct sigaction *handler, bool deadly)
 void
 user_debug_stop_thread()
 {
-	// prepare the message
-	debug_thread_debugged message;
+	// check whether this is actually an emulated single-step notification
+	InterruptsSpinLocker threadsLocker(gThreadSpinlock);
+	struct thread* thread = thread_get_current_thread();
+	bool singleStepped = false;
+	if ((atomic_and(&thread->debug_info.flags,
+				~B_THREAD_DEBUG_NOTIFY_SINGLE_STEP)
+			& B_THREAD_DEBUG_NOTIFY_SINGLE_STEP) != 0) {
+		singleStepped = true;
+	}
 
-	thread_hit_serious_debug_event(B_DEBUGGER_MESSAGE_THREAD_DEBUGGED, &message,
-		sizeof(message));
+	threadsLocker.Unlock();
+
+	if (singleStepped) {
+		user_debug_single_stepped();
+	} else {
+		debug_thread_debugged message;
+		thread_hit_serious_debug_event(B_DEBUGGER_MESSAGE_THREAD_DEBUGGED,
+			&message, sizeof(message));
+	}
 }