diff --git a/ntsys-assembler.h b/ntsys-assembler.h
index 7a79fd3..39ace16 100644
--- a/ntsys-assembler.h
+++ b/ntsys-assembler.h
@@ -39,7 +39,12 @@ int ntsys_compile_asm(char* filename, char* asm_out) {
     }
     rewind(fp);
     while ((st = ntsys_get_str(st, fp)) != NULL) {
-        if (ntsys_asm_from_string(&mem_pos, st, fw) != EXIT_SUCCESS) return EXIT_FAILURE;
+        if (ntsys_asm_from_string(&mem_pos, st, fw) != EXIT_SUCCESS) {
+            free(st);
+            fclose(fp);
+            fclose(fw);
+            return EXIT_FAILURE;
+        }
     }
     free(st);
     fclose(fp);