diff --git a/source/firm.c b/source/firm.c
index e0c4838..85ccb41 100755
--- a/source/firm.c
+++ b/source/firm.c
@@ -423,17 +423,19 @@ static __attribute__((noinline)) bool inRange(u32 as, u32 ae, u32 bs, u32 be)
    return false;
 }
 
-bool checkFirmPayload(void)
+bool checkFirmPayload(u32 payloadSize)
 {
     if(memcmp(firm->magic, "FIRM", 4) != 0 || firm->arm9Entry == NULL) //Allow for the ARM11 entrypoint to be zero in which case nothing is done on the ARM11 side
         return false;
 
+    bool arm9EpFound = false,
+         arm11EpFound = false;
+
     u32 size = 0x200;
     for(u32 i = 0; i < 4; i++)
         size += firm->section[i].size;
 
-    bool arm9EpFound = false,
-         arm11EpFound = false;
+    if(size != payloadSize) return false;
 
     for(u32 i = 0; i < 4; i++)
     {
diff --git a/source/firm.h b/source/firm.h
index 674b0a2..1320038 100644
--- a/source/firm.h
+++ b/source/firm.h
@@ -33,6 +33,5 @@ u32 patchTwlFirm(u32 firmVersion, bool loadFromStorage, bool doUnitinfoPatch);
 u32 patchAgbFirm(bool loadFromStorage, bool doUnitinfoPatch);
 u32 patch1x2xNativeAndSafeFirm(bool enableExceptionHandlers);
 
-bool checkFirmPayload(void);
+bool checkFirmPayload(u32 payloadSize);
 void launchFirm(int argc, char **argv);
-
diff --git a/source/fs.c b/source/fs.c
index 8192b68..63e4759 100644
--- a/source/fs.c
+++ b/source/fs.c
@@ -161,7 +161,7 @@ void loadPayload(u32 pressed, const char *payloadPath)
 
     payloadSize = fileRead(firm, path, maxPayloadSize);
 
-    if(payloadSize <= 0x200 || !checkFirmPayload()) return;
+    if(payloadSize <= 0x200 || !checkFirmPayload(payloadSize)) return;
 
     writeConfig(true);