diff --git a/include/exiv2/asfvideo.hpp b/include/exiv2/asfvideo.hpp
index d543ad9b..8b56d0bc 100644
--- a/include/exiv2/asfvideo.hpp
+++ b/include/exiv2/asfvideo.hpp
@@ -90,8 +90,8 @@ class EXIV2API AsfVideo : public Image {
 
   class HeaderReader {
     DataBuf IdBuf_;
-    uint64_t size_;
-    uint64_t remaining_size_;
+    uint64_t size_{};
+    uint64_t remaining_size_{};
 
    public:
     explicit HeaderReader(BasicIo::UniquePtr& io);
@@ -159,7 +159,8 @@ class EXIV2API AsfVideo : public Image {
 
  private:
   //! Variable to store height and width of a video frame.
-  uint64_t height_, width_;
+  uint64_t height_{};
+  uint64_t width_{};
 
 };  // Class AsfVideo
 
diff --git a/include/exiv2/matroskavideo.hpp b/include/exiv2/matroskavideo.hpp
index 4acf909f..a0c3470b 100644
--- a/include/exiv2/matroskavideo.hpp
+++ b/include/exiv2/matroskavideo.hpp
@@ -161,13 +161,13 @@ class EXIV2API MatroskaVideo : public Image {
 
  private:
   //! Variable to check the end of metadata traversing.
-  bool continueTraversing_;
+  bool continueTraversing_{};
   //! Variable to store height and width of a video frame.
-  uint64_t height_;
-  uint64_t width_;
-  uint32_t track_count_;
+  uint64_t height_{};
+  uint64_t width_{};
+  uint32_t track_count_{};
   double time_code_scale_ = 1.0;
-  uint64_t stream_ = 0;
+  uint64_t stream_{};
 
   static constexpr double bytesMB = 1048576;
 
diff --git a/include/exiv2/riffvideo.hpp b/include/exiv2/riffvideo.hpp
index 4112e11f..7610a0fc 100644
--- a/include/exiv2/riffvideo.hpp
+++ b/include/exiv2/riffvideo.hpp
@@ -169,7 +169,7 @@ class EXIV2API RiffVideo : public Image {
   static constexpr auto CHUNK_ID_VPRP = "VPRP";
   static constexpr auto CHUNK_ID_IDX1 = "IDX1";
 
-  int streamType_;
+  int streamType_{};
 
 };  // Class RiffVideo