diff --git a/c8_remote/src/exploit.c b/c8_remote/src/exploit.c
index de3e195..ce1d05f 100644
--- a/c8_remote/src/exploit.c
+++ b/c8_remote/src/exploit.c
@@ -150,6 +150,12 @@ int stage3_function(struct pwned_device *dev)
 
     checkm8_debug_indent("exploit stage 3\n");
     FILE *overwrite_file = fopen(CHECKM8_BIN_BASE "overwrite.bin", "r");
+    if(overwrite_file == NULL)
+    {
+        checkm8_debug_indent("\tfailed to open overwrite file\n");
+        return CHECKM8_FAIL_NOINST;
+    }
+
     fseek(overwrite_file, 0, SEEK_END);
     ow_len = ftell(overwrite_file);
     rewind(overwrite_file);
@@ -159,6 +165,12 @@ int stage3_function(struct pwned_device *dev)
     fclose(overwrite_file);
 
     FILE *payload_file = fopen(CHECKM8_BIN_BASE "payload.bin", "r");
+    if(payload_file == NULL)
+    {
+        checkm8_debug_indent("\tfailed to open payload file\n");
+        return CHECKM8_FAIL_NOINST;
+    }
+
     fseek(payload_file, 0, SEEK_END);
     pl_len = ftell(payload_file);
     rewind(payload_file);