diff --git a/src/PowderToySDL.cpp b/src/PowderToySDL.cpp
index 565dfb23e0..5a5cf0de2a 100644
--- a/src/PowderToySDL.cpp
+++ b/src/PowderToySDL.cpp
@@ -430,6 +430,12 @@ SDLKey MapNumpad(SDLKey key)
 		return KEY_HOME;
 	case KEY_NUM_END:
 		return KEY_END;
+	case KEY_NUM_PERIOD:
+		return KEY_DELETE;
+	case KEY_NUM_INS:
+	case KEY_NUM_PGUP:
+	case KEY_NUM_PGDOWN:
+		return KEY_UNKNOWN;
 	default:
 		return key;
 	}
diff --git a/src/gui/interface/Keys.h b/src/gui/interface/Keys.h
index 351e96e655..2707d4fdf3 100644
--- a/src/gui/interface/Keys.h
+++ b/src/gui/interface/Keys.h
@@ -1,6 +1,7 @@
 
 #if defined(USE_SDL)
 #include "SDL.h"
+#define KEY_UNKNOWN SDLK_UNKNOWN
 #define KEY_UP SDLK_UP
 #define KEY_NUM_UP SDLK_KP8
 #define KEY_DOWN SDLK_DOWN
@@ -13,14 +14,20 @@
 #define KEY_NUM_HOME SDLK_KP7
 #define KEY_END SDLK_END
 #define KEY_NUM_END SDLK_KP1
+#define KEY_NUM_INS SDLK_KP0
+#define KEY_NUM_PGUP SDLK_KP9
+#define KEY_NUM_PGDOWN SDLK_KP3
+#define KEY_NUM_PERIOD SDLK_KP_PERIOD
 #define KEY_BACKSPACE SDLK_BACKSPACE
-#define	KEY_DELETE SDLK_DELETE
+#define KEY_DELETE SDLK_DELETE
 #define KEY_TAB SDLK_TAB
 #define KEY_RETURN SDLK_RETURN
 #define KEY_ENTER SDLK_KP_ENTER
 #define KEY_ESCAPE SDLK_ESCAPE
 #define KEY_INSERT SDLK_INSERT
 
+#define KEY_NUM_5 SDLK_KP5
+
 #define KEY_LCTRL SDLK_LCTRL
 #define KEY_LALT SDLK_LALT
 #define KEY_LSHIFT SDLK_LSHIFT
@@ -62,6 +69,7 @@
 
 #else
 
+#define KEY_UNKNOWN 0
 #define KEY_UP 1
 #define KEY_NUM_UP 47
 #define KEY_DOWN 2
@@ -82,6 +90,12 @@
 #define KEY_ESCAPE 12
 #define KEY_INSERT 46
 
+#define KEY_NUM_INS 52
+#define KEY_NUM_PGUP 53
+#define KEY_NUM_PGDOWN 54
+#define KEY_NUM_PERIOD 55
+#define KEY_NUM_5 56
+
 #define KEY_LCTRL 13
 #define KEY_LALT 14
 #define KEY_LSHIFT 15