diff --git a/dlls/dinput/joystick.c b/dlls/dinput/joystick.c
index 19dd9ad7361..2eab4d3a33d 100644
--- a/dlls/dinput/joystick.c
+++ b/dlls/dinput/joystick.c
@@ -241,34 +241,42 @@ void dump_DIEFFECT(LPCDIEFFECT eff, REFGUID guid, DWORD dwFlags)
     if (type == DIEFT_CONSTANTFORCE) {
         if (eff->cbTypeSpecificParams != sizeof(DICONSTANTFORCE)) {
             WARN("Effect claims to be a constant force but the type-specific params are the wrong size!\n");
+        } else if (!eff->lpvTypeSpecificParams) {
+            WARN("Size of type-specific params is correct but pointer is NULL!\n");
         } else {
             _dump_DICONSTANTFORCE(eff->lpvTypeSpecificParams);
         }
     } else if (type == DIEFT_PERIODIC) {
         if (eff->cbTypeSpecificParams != sizeof(DIPERIODIC)) {
             WARN("Effect claims to be a periodic force but the type-specific params are the wrong size!\n");
+        } else if (!eff->lpvTypeSpecificParams) {
+            WARN("Size of type-specific params is correct but pointer is NULL!\n");
         } else {
             _dump_DIPERIODIC(eff->lpvTypeSpecificParams);
         }
     } else if (type == DIEFT_RAMPFORCE) {
         if (eff->cbTypeSpecificParams != sizeof(DIRAMPFORCE)) {
             WARN("Effect claims to be a ramp force but the type-specific params are the wrong size!\n");
+        } else if (!eff->lpvTypeSpecificParams) {
+            WARN("Size of type-specific params is correct but pointer is NULL!\n");
         } else {
             _dump_DIRAMPFORCE(eff->lpvTypeSpecificParams);
         }
     } else if (type == DIEFT_CONDITION) {
-        if (eff->cbTypeSpecificParams == sizeof(DICONDITION)) {
+        if (eff->cbTypeSpecificParams == sizeof(DICONDITION) && eff->lpvTypeSpecificParams) {
             _dump_DICONDITION(eff->lpvTypeSpecificParams);
-        } else if (eff->cbTypeSpecificParams == 2 * sizeof(DICONDITION)) {
+        } else if (eff->cbTypeSpecificParams == 2 * sizeof(DICONDITION) && eff->lpvTypeSpecificParams) {
             DICONDITION *condition = eff->lpvTypeSpecificParams;
             _dump_DICONDITION(&condition[0]);
             _dump_DICONDITION(&condition[1]);
         } else {
-            WARN("Effect claims to be a condition but the type-specific params are the wrong size!\n");
+            WARN("Effect claims to be a condition but the type-specific params are the wrong size or NULL!\n");
         }
     } else if (type == DIEFT_CUSTOMFORCE) {
         if (eff->cbTypeSpecificParams != sizeof(DICUSTOMFORCE)) {
             WARN("Effect claims to be a custom force but the type-specific params are the wrong size!\n");
+        } else if (!eff->lpvTypeSpecificParams) {
+            WARN("Size of type-specific params is correct but pointer is NULL!\n");
         } else {
             _dump_DICUSTOMFORCE(eff->lpvTypeSpecificParams);
         }