diff --git a/include/qpdf/ClosedFileInputSource.hh b/include/qpdf/ClosedFileInputSource.hh
index b5d7e33..f93764d 100644
--- a/include/qpdf/ClosedFileInputSource.hh
+++ b/include/qpdf/ClosedFileInputSource.hh
@@ -69,9 +69,9 @@ class QPDF_DLL_CLASS ClosedFileInputSource: public InputSource
     void after();
 
     std::string filename;
-    qpdf_offset_t offset;
+    qpdf_offset_t offset{0};
     std::shared_ptr<FileInputSource> fis;
-    bool stay_open;
+    bool stay_open{false};
 };
 
 #endif // QPDF_CLOSEDFILEINPUTSOURCE_HH
diff --git a/include/qpdf/QPDFAcroFormDocumentHelper.hh b/include/qpdf/QPDFAcroFormDocumentHelper.hh
index 248525a..db75226 100644
--- a/include/qpdf/QPDFAcroFormDocumentHelper.hh
+++ b/include/qpdf/QPDFAcroFormDocumentHelper.hh
@@ -234,10 +234,10 @@ class QPDFAcroFormDocumentHelper: public QPDFDocumentHelper
         ~Members() = default;
 
       private:
-        Members();
+        Members() = default;
         Members(Members const&) = delete;
 
-        bool cache_valid;
+        bool cache_valid{false};
         std::map<QPDFObjGen, std::vector<QPDFAnnotationObjectHelper>> field_to_annotations;
         std::map<QPDFObjGen, QPDFFormFieldObjectHelper> annotation_to_field;
         std::map<QPDFObjGen, std::string> field_to_name;
diff --git a/libqpdf/AES_PDF_native.cc b/libqpdf/AES_PDF_native.cc
index 42f1cda..8808d20 100644
--- a/libqpdf/AES_PDF_native.cc
+++ b/libqpdf/AES_PDF_native.cc
@@ -17,8 +17,7 @@ AES_PDF_native::AES_PDF_native(
     unsigned char* cbc_block) :
     encrypt(encrypt),
     cbc_mode(cbc_mode),
-    cbc_block(cbc_block),
-    nrounds(0)
+    cbc_block(cbc_block)
 {
     size_t keybits = 8 * key_bytes;
     this->key = std::make_unique<unsigned char[]>(key_bytes);
diff --git a/libqpdf/BitWriter.cc b/libqpdf/BitWriter.cc
index 2558592..c77eece 100644
--- a/libqpdf/BitWriter.cc
+++ b/libqpdf/BitWriter.cc
@@ -5,9 +5,7 @@
 #include <qpdf/bits_functions.hh>
 
 BitWriter::BitWriter(Pipeline* pl) :
-    pl(pl),
-    ch(0),
-    bit_offset(7)
+    pl(pl)
 {
 }
 
diff --git a/libqpdf/ClosedFileInputSource.cc b/libqpdf/ClosedFileInputSource.cc
index 2a6cb89..5995906 100644
--- a/libqpdf/ClosedFileInputSource.cc
+++ b/libqpdf/ClosedFileInputSource.cc
@@ -3,9 +3,7 @@
 #include <qpdf/FileInputSource.hh>
 
 ClosedFileInputSource::ClosedFileInputSource(char const* filename) :
-    filename(filename),
-    offset(0),
-    stay_open(false)
+    filename(filename)
 {
 }
 
diff --git a/libqpdf/ContentNormalizer.cc b/libqpdf/ContentNormalizer.cc
index 6ec6cf9..03496d4 100644
--- a/libqpdf/ContentNormalizer.cc
+++ b/libqpdf/ContentNormalizer.cc
@@ -5,12 +5,6 @@
 
 using namespace qpdf;
 
-ContentNormalizer::ContentNormalizer() :
-    any_bad_tokens(false),
-    last_token_was_bad(false)
-{
-}
-
 void
 ContentNormalizer::handleToken(QPDFTokenizer::Token const& token)
 {
diff --git a/libqpdf/InsecureRandomDataProvider.cc b/libqpdf/InsecureRandomDataProvider.cc
index 1c7fb9e..5c317e7 100644
--- a/libqpdf/InsecureRandomDataProvider.cc
+++ b/libqpdf/InsecureRandomDataProvider.cc
@@ -4,11 +4,6 @@
 #include <qpdf/qpdf-config.h>
 #include <cstdlib>
 
-InsecureRandomDataProvider::InsecureRandomDataProvider() :
-    seeded_random(false)
-{
-}
-
 void
 InsecureRandomDataProvider::provideRandomData(unsigned char* data, size_t len)
 {
diff --git a/libqpdf/NNTree.cc b/libqpdf/NNTree.cc
index fd7d437..210b8db 100644
--- a/libqpdf/NNTree.cc
+++ b/libqpdf/NNTree.cc
@@ -28,8 +28,7 @@ error(QPDF& qpdf, QPDFObjectHandle& node, std::string const& msg)
 }
 
 NNTreeIterator::NNTreeIterator(NNTreeImpl& impl) :
-    impl(impl),
-    item_number(-1)
+    impl(impl)
 {
 }
 
@@ -666,7 +665,6 @@ NNTreeImpl::NNTreeImpl(
     NNTreeDetails const& details, QPDF& qpdf, QPDFObjectHandle& oh, bool auto_repair) :
     details(details),
     qpdf(qpdf),
-    split_threshold(32),
     oh(oh),
     auto_repair(auto_repair)
 {
diff --git a/libqpdf/Pl_SHA2.cc b/libqpdf/Pl_SHA2.cc
index 090d778..9514d1c 100644
--- a/libqpdf/Pl_SHA2.cc
+++ b/libqpdf/Pl_SHA2.cc
@@ -5,8 +5,7 @@
 #include <stdexcept>
 
 Pl_SHA2::Pl_SHA2(int bits, Pipeline* next) :
-    Pipeline("sha2", next),
-    in_progress(false)
+    Pipeline("sha2", next)
 {
     if (bits) {
         resetBits(bits);
diff --git a/libqpdf/QPDFAcroFormDocumentHelper.cc b/libqpdf/QPDFAcroFormDocumentHelper.cc
index 5c513c3..aa54d81 100644
--- a/libqpdf/QPDFAcroFormDocumentHelper.cc
+++ b/libqpdf/QPDFAcroFormDocumentHelper.cc
@@ -9,11 +9,6 @@
 
 using namespace qpdf;
 
-QPDFAcroFormDocumentHelper::Members::Members() :
-    cache_valid(false)
-{
-}
-
 QPDFAcroFormDocumentHelper::QPDFAcroFormDocumentHelper(QPDF& qpdf) :
     QPDFDocumentHelper(qpdf),
     m(new Members())
diff --git a/libqpdf/QPDFArgParser.cc b/libqpdf/QPDFArgParser.cc
index 9490fa5..18cb501 100644
--- a/libqpdf/QPDFArgParser.cc
+++ b/libqpdf/QPDFArgParser.cc
@@ -18,12 +18,7 @@ QPDFArgParser::Members::Members(int argc, char const* const argv[], char const* 
 
     argc(argc),
     argv(argv),
-    progname_env(progname_env),
-    cur_arg(0),
-    bash_completion(false),
-    zsh_completion(false),
-    option_table(nullptr),
-    final_check_handler(nullptr)
+    progname_env(progname_env)
 {
     auto tmp = QUtil::make_unique_cstr(argv[0]);
     whoami = QUtil::getWhoami(tmp.get());
diff --git a/libqpdf/ResourceFinder.cc b/libqpdf/ResourceFinder.cc
index 798fe67..06d37e1 100644
--- a/libqpdf/ResourceFinder.cc
+++ b/libqpdf/ResourceFinder.cc
@@ -1,10 +1,5 @@
 #include <qpdf/ResourceFinder.hh>
 
-ResourceFinder::ResourceFinder() :
-    last_name_offset(0)
-{
-}
-
 void
 ResourceFinder::handleObject(QPDFObjectHandle obj, size_t offset, size_t)
 {
diff --git a/libqpdf/qpdf/AES_PDF_native.hh b/libqpdf/qpdf/AES_PDF_native.hh
index 0b93203..527e8cb 100644
--- a/libqpdf/qpdf/AES_PDF_native.hh
+++ b/libqpdf/qpdf/AES_PDF_native.hh
@@ -25,7 +25,7 @@ class AES_PDF_native
     unsigned char* cbc_block;
     std::unique_ptr<unsigned char[]> key;
     std::unique_ptr<uint32_t[]> rk;
-    unsigned int nrounds;
+    unsigned int nrounds{0};
 };
 
 #endif // AES_PDF_NATIVE_HH
diff --git a/libqpdf/qpdf/BitWriter.hh b/libqpdf/qpdf/BitWriter.hh
index 24c7416..9b8e2bc 100644
--- a/libqpdf/qpdf/BitWriter.hh
+++ b/libqpdf/qpdf/BitWriter.hh
@@ -21,8 +21,8 @@ class BitWriter
 
   private:
     Pipeline* pl;
-    unsigned char ch;
-    size_t bit_offset;
+    unsigned char ch{0};
+    size_t bit_offset{7};
 };
 
 #endif // BITWRITER_HH
diff --git a/libqpdf/qpdf/ContentNormalizer.hh b/libqpdf/qpdf/ContentNormalizer.hh
index 930cf14..7c3b6d2 100644
--- a/libqpdf/qpdf/ContentNormalizer.hh
+++ b/libqpdf/qpdf/ContentNormalizer.hh
@@ -6,7 +6,7 @@
 class ContentNormalizer final: public QPDFObjectHandle::TokenFilter
 {
   public:
-    ContentNormalizer();
+    ContentNormalizer() = default;
     ~ContentNormalizer() final = default;
     void handleToken(QPDFTokenizer::Token const&) final;
 
@@ -22,8 +22,8 @@ class ContentNormalizer final: public QPDFObjectHandle::TokenFilter
     }
 
   private:
-    bool any_bad_tokens;
-    bool last_token_was_bad;
+    bool any_bad_tokens{false};
+    bool last_token_was_bad{false};
 };
 
 #endif // CONTENTNORMALIZER_HH
diff --git a/libqpdf/qpdf/InsecureRandomDataProvider.hh b/libqpdf/qpdf/InsecureRandomDataProvider.hh
index bab4e00..b9870d1 100644
--- a/libqpdf/qpdf/InsecureRandomDataProvider.hh
+++ b/libqpdf/qpdf/InsecureRandomDataProvider.hh
@@ -3,18 +3,18 @@
 
 #include <qpdf/RandomDataProvider.hh>
 
-class InsecureRandomDataProvider: public RandomDataProvider
+class InsecureRandomDataProvider final: public RandomDataProvider
 {
   public:
-    InsecureRandomDataProvider();
-    ~InsecureRandomDataProvider() override = default;
-    void provideRandomData(unsigned char* data, size_t len) override;
+    InsecureRandomDataProvider() = default;
+    ~InsecureRandomDataProvider() final = default;
+    void provideRandomData(unsigned char* data, size_t len) final;
     static RandomDataProvider* getInstance();
 
   private:
     long random();
 
-    bool seeded_random;
+    bool seeded_random{false};
 };
 
 #endif // INSECURERANDOMDATAPROVIDER_HH
diff --git a/libqpdf/qpdf/NNTree.hh b/libqpdf/qpdf/NNTree.hh
index 4b5ba20..e62e959 100644
--- a/libqpdf/qpdf/NNTree.hh
+++ b/libqpdf/qpdf/NNTree.hh
@@ -84,7 +84,7 @@ class NNTreeIterator
     NNTreeImpl& impl;
     std::list<PathElement> path;
     QPDFObjectHandle node;
-    int item_number;
+    int item_number{-1};
     value_type ivalue;
 };
 
@@ -123,7 +123,7 @@ class NNTreeImpl
 
     NNTreeDetails const& details;
     QPDF& qpdf;
-    int split_threshold;
+    int split_threshold{32};
     QPDFObjectHandle oh;
     bool auto_repair;
 };
diff --git a/libqpdf/qpdf/Pl_SHA2.hh b/libqpdf/qpdf/Pl_SHA2.hh
index ee4c5c1..e3d924b 100644
--- a/libqpdf/qpdf/Pl_SHA2.hh
+++ b/libqpdf/qpdf/Pl_SHA2.hh
@@ -25,7 +25,7 @@ class Pl_SHA2 final: public Pipeline
     std::string getRawDigest();
 
   private:
-    bool in_progress;
+    bool in_progress{false};
     std::shared_ptr<QPDFCryptoImpl> crypto;
 };
 
diff --git a/libqpdf/qpdf/QPDFArgParser.hh b/libqpdf/qpdf/QPDFArgParser.hh
index f5c9620..7e4c92e 100644
--- a/libqpdf/qpdf/QPDFArgParser.hh
+++ b/libqpdf/qpdf/QPDFArgParser.hh
@@ -206,9 +206,9 @@ class QPDFArgParser
         char const* const* argv;
         std::string whoami;
         std::string progname_env;
-        int cur_arg;
-        bool bash_completion;
-        bool zsh_completion;
+        int cur_arg{0};
+        bool bash_completion{false};
+        bool zsh_completion{false};
         std::string bash_prev;
         std::string bash_cur;
         std::string bash_line;
@@ -216,9 +216,9 @@ class QPDFArgParser
         std::map<std::string, option_table_t> option_tables;
         option_table_t main_option_table;
         option_table_t help_option_table;
-        option_table_t* option_table;
+        option_table_t* option_table{nullptr};
         std::string option_table_name;
-        bare_arg_handler_t final_check_handler;
+        bare_arg_handler_t final_check_handler{nullptr};
         std::vector<std::string> new_argv;
         std::vector<std::string> bash_argv;
         std::vector<char const*> argv_ph;
diff --git a/libqpdf/qpdf/QPDFCrypto_native.hh b/libqpdf/qpdf/QPDFCrypto_native.hh
index 4dd6362..9ac0d75 100644
--- a/libqpdf/qpdf/QPDFCrypto_native.hh
+++ b/libqpdf/qpdf/QPDFCrypto_native.hh
@@ -8,37 +8,37 @@
 #include <qpdf/SHA2_native.hh>
 #include <memory>
 
-class QPDFCrypto_native: public QPDFCryptoImpl
+class QPDFCrypto_native final: public QPDFCryptoImpl
 {
   public:
     QPDFCrypto_native() = default;
 
-    virtual ~QPDFCrypto_native() = default;
+    ~QPDFCrypto_native() final = default;
 
-    virtual void provideRandomData(unsigned char* data, size_t len);
+    void provideRandomData(unsigned char* data, size_t len) final;
 
-    virtual void MD5_init();
-    virtual void MD5_update(unsigned char const* data, size_t len);
-    virtual void MD5_finalize();
-    virtual void MD5_digest(MD5_Digest);
+    void MD5_init() final;
+    void MD5_update(unsigned char const* data, size_t len) final;
+    void MD5_finalize() final;
+    void MD5_digest(MD5_Digest) final;
 
-    virtual void RC4_init(unsigned char const* key_data, int key_len = -1);
-    virtual void RC4_process(unsigned char const* in_data, size_t len, unsigned char* out_data = 0);
-    virtual void RC4_finalize();
+    void RC4_init(unsigned char const* key_data, int key_len = -1) final;
+    void RC4_process(unsigned char const* in_data, size_t len, unsigned char* out_data = 0) final;
+    void RC4_finalize() final;
 
-    virtual void SHA2_init(int bits);
-    virtual void SHA2_update(unsigned char const* data, size_t len);
-    virtual void SHA2_finalize();
-    virtual std::string SHA2_digest();
+    void SHA2_init(int bits) final;
+    void SHA2_update(unsigned char const* data, size_t len) final;
+    void SHA2_finalize() final;
+    std::string SHA2_digest() final;
 
-    virtual void rijndael_init(
+    void rijndael_init(
         bool encrypt,
         unsigned char const* key_data,
         size_t key_len,
         bool cbc_mode,
-        unsigned char* cbc_block);
-    virtual void rijndael_process(unsigned char* in_data, unsigned char* out_data);
-    virtual void rijndael_finalize();
+        unsigned char* cbc_block) final;
+    void rijndael_process(unsigned char* in_data, unsigned char* out_data) final;
+    void rijndael_finalize() final;
 
   private:
     std::shared_ptr<MD5_native> md5;
diff --git a/libqpdf/qpdf/ResourceFinder.hh b/libqpdf/qpdf/ResourceFinder.hh
index 1c4c59a..04614d7 100644
--- a/libqpdf/qpdf/ResourceFinder.hh
+++ b/libqpdf/qpdf/ResourceFinder.hh
@@ -3,20 +3,20 @@
 
 #include <qpdf/QPDFObjectHandle.hh>
 
-class ResourceFinder: public QPDFObjectHandle::ParserCallbacks
+class ResourceFinder final: public QPDFObjectHandle::ParserCallbacks
 {
   public:
-    ResourceFinder();
-    ~ResourceFinder() override = default;
-    void handleObject(QPDFObjectHandle, size_t, size_t) override;
-    void handleEOF() override;
+    ResourceFinder() = default;
+    ~ResourceFinder() final = default;
+    void handleObject(QPDFObjectHandle, size_t, size_t) final;
+    void handleEOF() final;
     std::set<std::string> const& getNames() const;
     std::map<std::string, std::map<std::string, std::set<size_t>>> const&
     getNamesByResourceType() const;
 
   private:
     std::string last_name;
-    size_t last_name_offset;
+    size_t last_name_offset{0};
     std::set<std::string> names;
     std::map<std::string, std::map<std::string, std::set<size_t>>> names_by_resource_type;
 };