diff --git a/ui/cocoa.m b/ui/cocoa.m
index 004ec27..1f010d3 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -52,6 +52,8 @@
 /* macOS 10.12 deprecated many constants, #define the new names for older SDKs */
 #if MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_12
 #define NSEventMaskAny                  NSAnyEventMask
+#define NSEventModifierFlagCapsLock     NSAlphaShiftKeyMask
+#define NSEventModifierFlagShift        NSShiftKeyMask
 #define NSEventModifierFlagCommand      NSCommandKeyMask
 #define NSEventModifierFlagControl      NSControlKeyMask
 #define NSEventModifierFlagOption       NSAlternateKeyMask
@@ -268,7 +270,7 @@
     NSWindow *fullScreenWindow;
     float cx,cy,cw,ch,cdx,cdy;
     CGDataProviderRef dataProviderRef;
-    int modifiers_state[256];
+    BOOL modifiers_state[256];
     BOOL isMouseGrabbed;
     BOOL isFullscreen;
     BOOL isAbsoluteEnabled;
@@ -536,18 +538,59 @@
     }
 }
 
+- (void) toggleModifier: (int)keycode {
+    // Toggle the stored state.
+    modifiers_state[keycode] = !modifiers_state[keycode];
+    // Send a keyup or keydown depending on the state.
+    qemu_input_event_send_key_qcode(dcl->con, keycode, modifiers_state[keycode]);
+}
+
+- (void) toggleStatefulModifier: (int)keycode {
+    // Toggle the stored state.
+    modifiers_state[keycode] = !modifiers_state[keycode];
+    // Generate keydown and keyup.
+    qemu_input_event_send_key_qcode(dcl->con, keycode, true);
+    qemu_input_event_send_key_qcode(dcl->con, keycode, false);
+}
+
 - (void) handleEvent:(NSEvent *)event
 {
     COCOA_DEBUG("QemuCocoaView: handleEvent\n");
 
     int buttons = 0;
-    int keycode;
+    int keycode = 0;
     bool mouse_event = false;
     NSPoint p = [event locationInWindow];
 
     switch ([event type]) {
         case NSEventTypeFlagsChanged:
-            keycode = cocoa_keycode_to_qemu([event keyCode]);
+            if ([event keyCode] == 0) {
+                // When the Cocoa keyCode is zero that means keys should be
+                // synthesized based on the values in in the eventModifiers
+                // bitmask.
+
+                if (qemu_console_is_graphic(NULL)) {
+                    NSEventModifierFlags modifiers = [event modifierFlags];
+
+                    if (!!(modifiers & NSEventModifierFlagCapsLock) != !!modifiers_state[Q_KEY_CODE_CAPS_LOCK]) {
+                        [self toggleStatefulModifier:Q_KEY_CODE_CAPS_LOCK];
+                    }
+                    if (!!(modifiers & NSEventModifierFlagShift) != !!modifiers_state[Q_KEY_CODE_SHIFT]) {
+                        [self toggleModifier:Q_KEY_CODE_SHIFT];
+                    }
+                    if (!!(modifiers & NSEventModifierFlagControl) != !!modifiers_state[Q_KEY_CODE_CTRL]) {
+                        [self toggleModifier:Q_KEY_CODE_CTRL];
+                    }
+                    if (!!(modifiers & NSEventModifierFlagOption) != !!modifiers_state[Q_KEY_CODE_ALT]) {
+                        [self toggleModifier:Q_KEY_CODE_ALT];
+                    }
+                    if (!!(modifiers & NSEventModifierFlagCommand) != !!modifiers_state[Q_KEY_CODE_META_L]) {
+                        [self toggleModifier:Q_KEY_CODE_META_L];
+                    }
+                }
+            } else {
+                keycode = cocoa_keycode_to_qemu([event keyCode]);
+            }
 
             if ((keycode == Q_KEY_CODE_META_L || keycode == Q_KEY_CODE_META_R)
                && !isMouseGrabbed) {
@@ -559,16 +602,9 @@
                 // emulate caps lock and num lock keydown and keyup
                 if (keycode == Q_KEY_CODE_CAPS_LOCK ||
                     keycode == Q_KEY_CODE_NUM_LOCK) {
-                    qemu_input_event_send_key_qcode(dcl->con, keycode, true);
-                    qemu_input_event_send_key_qcode(dcl->con, keycode, false);
+                    [self toggleStatefulModifier:keycode];
                 } else if (qemu_console_is_graphic(NULL)) {
-                    if (modifiers_state[keycode] == 0) { // keydown
-                        qemu_input_event_send_key_qcode(dcl->con, keycode, true);
-                        modifiers_state[keycode] = 1;
-                    } else { // keyup
-                        qemu_input_event_send_key_qcode(dcl->con, keycode, false);
-                        modifiers_state[keycode] = 0;
-                    }
+                  [self toggleModifier:keycode];
                 }
             }