diff --git a/src/posix/sdl/i_input.cpp b/src/posix/sdl/i_input.cpp
index 1d47dd6e0..759da062c 100644
--- a/src/posix/sdl/i_input.cpp
+++ b/src/posix/sdl/i_input.cpp
@@ -336,6 +336,12 @@ void MessagePump (const SDL_Event &sev)
 				event.subtype = sev.type == SDL_MOUSEBUTTONDOWN ? EV_GUI_LButtonDown : EV_GUI_LButtonUp;
 				event.subtype += (sev.button.button - 1) * 3;
 			}
+
+			SDL_Keymod kmod = SDL_GetModState();
+			event.data3 = ((kmod & KMOD_SHIFT) ? GKM_SHIFT : 0) |
+				((kmod & KMOD_CTRL) ? GKM_CTRL : 0) |
+				((kmod & KMOD_ALT) ? GKM_ALT : 0);
+
 			D_PostEvent(&event);
 		}
 		break;
@@ -345,6 +351,10 @@ void MessagePump (const SDL_Event &sev)
 		{
 			event.type = EV_GUI_Event;
 			event.subtype = sev.wheel.y > 0 ? EV_GUI_WheelUp : EV_GUI_WheelDown;
+			SDL_Keymod kmod = SDL_GetModState();
+			event.data3 = ((kmod & KMOD_SHIFT) ? GKM_SHIFT : 0) |
+				((kmod & KMOD_CTRL) ? GKM_CTRL : 0) |
+				((kmod & KMOD_ALT) ? GKM_ALT : 0);
 			D_PostEvent (&event);
 		}
 		else