diff --git a/src/qcir/qcir_reader.cpp b/src/qcir/qcir_reader.cpp
index 4ecf2260..1fe0a189 100644
--- a/src/qcir/qcir_reader.cpp
+++ b/src/qcir/qcir_reader.cpp
@@ -48,7 +48,7 @@ std::optional<QCir> from_qasm(std::filesystem::path const& filepath) {
     using dvlab::str::str_get_token;
 
     // read file and open
-    std::fstream qasm_file{filepath};
+    std::ifstream qasm_file{filepath};
     if (!qasm_file.is_open()) {
         spdlog::error("Cannot open the QASM file \"{}\"!!", filepath);
         return std::nullopt;
@@ -122,7 +122,7 @@ std::optional<QCir> from_qasm(std::filesystem::path const& filepath) {
 std::optional<QCir> from_qc(std::filesystem::path const& filepath) {
     using dvlab::str::str_get_token;
     // read file and open
-    std::fstream qc_file{filepath};
+    std::ifstream qc_file{filepath};
     if (!qc_file.is_open()) {
         spdlog::error("Cannot open the QC file \"{}\"!!", filepath);
         return std::nullopt;
diff --git a/src/zx/zx_io.cpp b/src/zx/zx_io.cpp
index 80c1128c..8eee50f5 100644
--- a/src/zx/zx_io.cpp
+++ b/src/zx/zx_io.cpp
@@ -565,7 +565,7 @@ bool ZXGraph::write_tikz(std::string const& filename) const {
 }
 
 /**
- * @brief write tikz file to the fstream `tikzFile`
+ * @brief write tikz file to the ostream `tikzFile`
  *
  * @param tikzFile
  * @return true if the filename is valid