diff --git a/autotests/ossfuzz/build_fuzzers.sh b/autotests/ossfuzz/build_fuzzers.sh
index f9c6019..ccb333a 100755
--- a/autotests/ossfuzz/build_fuzzers.sh
+++ b/autotests/ossfuzz/build_fuzzers.sh
@@ -26,8 +26,8 @@ export LDFLAGS
 
 # build zstd
 cd $SRC/zstd
-cmake -S build/cmake -DBUILD_SHARED_LIBS=OFF
-make install -j$(nproc)
+cmake -G Ninja -S build/cmake -DBUILD_SHARED_LIBS=OFF -DZSTD_BUILD_PROGRAMS=OFF -DBUILD_TESTING=OFF
+ninja install
 
 # Build zlib
 cd $SRC/zlib
@@ -70,13 +70,13 @@ cmake --install .
 
 # Build extra-cmake-modules
 cd $SRC/extra-cmake-modules
-cmake . -DBUILD_TESTING=OFF
-make install -j$(nproc)
+cmake -G Ninja . -DBUILD_TESTING=OFF -DBUILD_DOC=OFF
+ninja install
 
 cd $SRC/karchive
 rm -rf poqm
-cmake . -DBUILD_SHARED_LIBS=OFF -DBUILD_TESTING=OFF -DCMAKE_INSTALL_PREFIX=/usr/local
-make install -j$(nproc)
+cmake -G Ninja . -DBUILD_SHARED_LIBS=OFF -DBUILD_TESTING=OFF -DCMAKE_INSTALL_PREFIX=/usr/local
+ninja install
 
 # Build JXRlib
 cd $SRC/jxrlib
@@ -101,31 +101,28 @@ cd $SRC/aom
 mkdir build.libavif
 cd build.libavif
 extra_libaom_flags='-DAOM_MAX_ALLOCABLE_MEMORY=536870912 -DDO_RANGE_CHECK_CLAMP=1'
-cmake -DBUILD_SHARED_LIBS=0 -DENABLE_DOCS=0 -DENABLE_EXAMPLES=0 -DENABLE_TESTDATA=0 -DENABLE_TESTS=0 -DENABLE_TOOLS=0 -DCONFIG_PIC=1 -DAOM_TARGET_CPU=generic -DCONFIG_SIZE_LIMIT=1 -DDECODE_HEIGHT_LIMIT=12288 -DDECODE_WIDTH_LIMIT=12288 -DAOM_EXTRA_C_FLAGS="${extra_libaom_flags}" -DAOM_EXTRA_CXX_FLAGS="${extra_libaom_flags}" ..
-make -j$(nproc)
-make install -j$(nproc)
+cmake -G Ninja -DBUILD_SHARED_LIBS=0 -DENABLE_DOCS=0 -DENABLE_EXAMPLES=0 -DENABLE_TESTDATA=0 -DENABLE_TESTS=0 -DENABLE_TOOLS=0 -DCONFIG_PIC=1 -DAOM_TARGET_CPU=generic -DCONFIG_SIZE_LIMIT=1 -DDECODE_HEIGHT_LIMIT=12288 -DDECODE_WIDTH_LIMIT=12288 -DAOM_EXTRA_C_FLAGS="${extra_libaom_flags}" -DAOM_EXTRA_CXX_FLAGS="${extra_libaom_flags}" ..
+ninja install
 
 # Build libavif
 cd $SRC/libavif
 ln -s "$SRC/aom" "$SRC/libavif/ext/"
 mkdir build
 cd build
-CFLAGS="$CFLAGS -fPIC" cmake -DBUILD_SHARED_LIBS=OFF -DAVIF_ENABLE_WERROR=OFF -DAVIF_CODEC_AOM=LOCAL -DAVIF_LIBYUV=OFF ..
-make -j$(nproc)
+CFLAGS="$CFLAGS -fPIC" cmake -G Ninja -DBUILD_SHARED_LIBS=OFF -DAVIF_ENABLE_WERROR=OFF -DAVIF_CODEC_AOM=LOCAL -DAVIF_LIBYUV=OFF ..
+ninja
 
 # Build libde265
 cd $SRC/libde265
-cmake -DBUILD_SHARED_LIBS=OFF -DENABLE_SDL=OFF -DENABLE_SIMD=OFF -DENABLE_AVX2=OFF -DENABLE_AVX512=OFF .
-make -j$(nproc)
-make install -j$(nproc)
+cmake -G Ninja -DBUILD_SHARED_LIBS=OFF -DENABLE_SDL=OFF -DENABLE_SIMD=OFF -DENABLE_AVX2=OFF -DENABLE_AVX512=OFF .
+ninja install
 
 # Build openjpeg
 cd $SRC/openjpeg
 mkdir build
 cd build
-cmake -DBUILD_SHARED_LIBS=OFF -DBUILD_STATIC_LIBS=ON -DBUILD_CODEC=OFF ..
-make -j$(nproc)
-make install -j$(nproc)
+cmake -G Ninja -DBUILD_SHARED_LIBS=OFF -DBUILD_STATIC_LIBS=ON -DBUILD_CODEC=OFF ..
+ninja install
 
 # build openh264
 cd $SRC/openh264
@@ -135,17 +132,15 @@ make USE_ASM=No BUILDTYPE=Debug install-static -j$(nproc)
 cd $SRC/openexr
 mkdir _build
 cd _build
-cmake  -DBUILD_SHARED_LIBS=OFF ..
-make -j$(nproc)
-make install -j$(nproc)
+cmake -G Ninja -DBUILD_SHARED_LIBS=OFF -DBUILD_TESTING=OFF -DOPENEXR_BUILD_TOOLS=OFF -DOPENEXR_INSTALL_TOOLS=OFF -DOPENEXR_BUILD_EXAMPLES=OFF -DOPENEXR_TEST_LIBRARIES=OFF -DOPENEXR_TEST_TOOLS=OFF -DOPENEXR_TEST_PYTHON=OFF ..
+ninja install
 
 # Build libjxl
 cd $SRC/libjxl
 mkdir build
 cd build
-CXXFLAGS="$CXXFLAGS -DHWY_COMPILE_ONLY_SCALAR" cmake -DBUILD_SHARED_LIBS=OFF -DBUILD_TESTING=OFF -DJPEGXL_ENABLE_BENCHMARK=OFF -DJPEGXL_ENABLE_DOXYGEN=OFF -DJPEGXL_ENABLE_EXAMPLES=OFF -DJPEGXL_ENABLE_JNI=OFF  -DJPEGXL_ENABLE_MANPAGES=OFF -DJPEGXL_ENABLE_OPENEXR=OFF -DJPEGXL_ENABLE_PLUGINS=OFF -DJPEGXL_ENABLE_SJPEG=OFF -DJPEGXL_ENABLE_SKCMS=ON -DJPEGXL_ENABLE_TCMALLOC=OFF -DJPEGXL_ENABLE_TOOLS=OFF -DJPEGXL_ENABLE_FUZZERS=OFF ..
-make -j$(nproc) jxl jxl_cms jxl_threads
-make install -j$(nproc)
+CXXFLAGS="$CXXFLAGS -DHWY_COMPILE_ONLY_SCALAR" cmake -G Ninja -DBUILD_SHARED_LIBS=OFF -DBUILD_TESTING=OFF -DJPEGXL_ENABLE_BENCHMARK=OFF -DJPEGXL_ENABLE_DOXYGEN=OFF -DJPEGXL_ENABLE_EXAMPLES=OFF -DJPEGXL_ENABLE_JNI=OFF  -DJPEGXL_ENABLE_MANPAGES=OFF -DJPEGXL_ENABLE_OPENEXR=OFF -DJPEGXL_ENABLE_PLUGINS=OFF -DJPEGXL_ENABLE_SJPEG=OFF -DJPEGXL_ENABLE_SKCMS=ON -DJPEGXL_ENABLE_TCMALLOC=OFF -DJPEGXL_ENABLE_TOOLS=OFF -DJPEGXL_ENABLE_FUZZERS=OFF ..
+ninja install
 
 # Build libheif
 cd $SRC/libheif
@@ -154,49 +149,51 @@ sed -i "s/static const int MAX_IMAGE_WIDTH = 32768;/static const int MAX_IMAGE_W
 sed -i "s/static const int MAX_IMAGE_HEIGHT = 32768;/static const int MAX_IMAGE_HEIGHT = 8192;/g" libheif/security_limits.h
 mkdir build
 cd build
-cmake -DBUILD_SHARED_LIBS=OFF -DBUILD_TESTING=OFF -DENABLE_PLUGIN_LOADING=OFF -DWITH_EXAMPLES=OFF -DBUILD_DOCUMENTATION=OFF -DWITH_LIBSHARPYUV=OFF -DWITH_UNCOMPRESSED_CODEC=ON -DWITH_DAV1D=OFF -DWITH_EXAMPLES=OFF -DWITH_LIBDE265=ON -DWITH_RAV1E=OFF -DWITH_RAV1E_PLUGIN=OFF -DWITH_SvtEnc=OFF -DWITH_SvtEnc_PLUGIN=OFF -DWITH_X265=OFF -DWITH_X264=OFF -DWITH_OpenJPEG_DECODER=ON -DWITH_OpenH264_DECODER=ON ..
-make -j$(nproc)
-make install -j$(nproc)
+cmake -G Ninja -DBUILD_SHARED_LIBS=OFF -DBUILD_TESTING=OFF -DENABLE_PLUGIN_LOADING=OFF -DWITH_EXAMPLES=OFF -DBUILD_DOCUMENTATION=OFF -DWITH_LIBSHARPYUV=OFF -DWITH_UNCOMPRESSED_CODEC=ON -DWITH_DAV1D=OFF -DWITH_EXAMPLES=OFF -DWITH_LIBDE265=ON -DWITH_RAV1E=OFF -DWITH_RAV1E_PLUGIN=OFF -DWITH_SvtEnc=OFF -DWITH_SvtEnc_PLUGIN=OFF -DWITH_X265=OFF -DWITH_X264=OFF -DWITH_OpenJPEG_DECODER=ON -DWITH_OpenH264_DECODER=ON ..
+ninja install
 
 cd $SRC/kimageformats
-HANDLER_TYPES="ANIHandler ani
-        QAVIFHandler avif
-        QDDSHandler dds
-        EXRHandler exr
-        FFHandler ff
-        HDRHandler hdr
-        HEIFHandler heif
-        IFFHandler iff
-        JP2Handler jp2
-        QJpegXLHandler jxl
-        JXRHandler jxr
-        KraHandler kra
-        OraHandler ora
-        PCXHandler pcx
-        PFMHandler pfm
-        SoftimagePICHandler pic
-        PSDHandler psd
-        PXRHandler pxr
-        QOIHandler qoi
-        RASHandler ras
-        RAWHandler raw
-        RGBHandler rgb
-        ScitexHandler sct
-        TIMHandler tim
-        TGAHandler tga
-        XCFHandler xcf"
+HANDLER_TYPES="ani
+        avif
+        dds
+        exr
+        ff
+        hdr
+        heif
+        iff
+        jp2
+        jxl
+        jxr
+        kra
+        ora
+        pcx
+        pfm
+        pic
+        psd
+        pxr
+        qoi
+        ras
+        raw
+        rgb
+        sct
+        tim
+        tga
+        xcf"
 
-echo "$HANDLER_TYPES" | while read class format; do
+echo "$HANDLER_TYPES" | while read format; do
 (
   fuzz_target_name=kimgio_${format}_fuzzer
 
   /usr/libexec/moc $SRC/kimageformats/src/imageformats/$format.cpp -o $format.moc
   header=`ls $SRC/kimageformats/src/imageformats/$format*.h`
   /usr/libexec/moc $header -o moc_`basename $header .h`.cpp
-  $CXX $CXXFLAGS $LDFLAGS -fPIC -DHANDLER=$class -std=c++17 autotests/ossfuzz/kimgio_fuzzer.cc $SRC/kimageformats/src/imageformats/$format.cpp $SRC/kimageformats/src/imageformats/scanlineconverter.cpp $SRC/kimageformats/src/imageformats/microexif.cpp $SRC/kimageformats/src/imageformats/chunks.cpp -o $OUT/$fuzz_target_name -DJXL_STATIC_DEFINE -DJXL_THREADS_STATIC_DEFINE -DJXL_CMS_STATIC_DEFINE -D__ANSI__ -I $SRC/kimageformats/src/imageformats/ -I $SRC/libavif/include/ -I $SRC/libjxl/build/lib/include/ -I $SRC/libjxl/lib/include/ -I /usr/local/include/OpenEXR/ -I /usr/local/include/KF6/KArchive/ -I /usr/local/include/openjpeg-2.5 -I /usr/local/include/Imath -I $SRC/jxrlib/common/include -I $SRC/jxrlib/jxrgluelib -I $SRC/jxrlib/image/sys -I /usr/include/QtCore/ -I /usr/include/QtGui/ -I . $SRC/libavif/build/libavif.a /usr/local/lib/libheif.a /usr/local/lib/libde265.a /usr/local/lib/libopenh264.a $SRC/aom/build.libavif/libaom.a $SRC/libjxl/build/lib/libjxl_threads.a $SRC/libjxl/build/lib/libjxl.a $SRC/libjxl/build/lib/libjxl_cms.a $SRC/libjxl/build/third_party/highway/libhwy.a $SRC/libjxl/build/third_party/brotli/libbrotlidec.a $SRC/libjxl/build/third_party/brotli/libbrotlienc.a $SRC/libjxl/build/third_party/brotli/libbrotlicommon.a -lQt6Gui -lQt6Core -lQt6BundledLibpng -lQt6BundledHarfbuzz -lm -lQt6BundledPcre2 -ldl -lpthread $LIB_FUZZING_ENGINE /usr/local/lib/libz.a /usr/local/lib/x86_64-linux-gnu/libKF6Archive.a /usr/local/lib/libz.a /usr/local/lib/libraw.a /usr/local/lib/libOpenEXR-3_3.a /usr/local/lib/libIex-3_3.a /usr/local/lib/libImath-3_1.a /usr/local/lib/libIlmThread-3_3.a /usr/local/lib/libOpenEXRCore-3_3.a /usr/local/lib/libOpenEXRUtil-3_3.a /usr/local/lib/libopenjp2.a /usr/local/lib/libzstd.a $SRC/jxrlib/build/libjxrglue.a $SRC/jxrlib/build/libjpegxr.a /usr/local/lib/liblzma.a /usr/local/lib/libbz2.a -lclang_rt.builtins
+  $CXX $CXXFLAGS $LDFLAGS -fPIC -DKIMG_FUZZER_${format}=1 -std=c++17 autotests/ossfuzz/kimgio_fuzzer.cc $SRC/kimageformats/src/imageformats/$format.cpp $SRC/kimageformats/src/imageformats/scanlineconverter.cpp $SRC/kimageformats/src/imageformats/microexif.cpp $SRC/kimageformats/src/imageformats/chunks.cpp -o $OUT/$fuzz_target_name -DJXL_STATIC_DEFINE -DJXL_THREADS_STATIC_DEFINE -DJXL_CMS_STATIC_DEFINE -D__ANSI__ -I $SRC/kimageformats/src/imageformats/ -I $SRC/libavif/include/ -I $SRC/libjxl/build/lib/include/ -I $SRC/libjxl/lib/include/ -I /usr/local/include/OpenEXR/ -I /usr/local/include/KF6/KArchive/ -I /usr/local/include/openjpeg-2.5 -I /usr/local/include/Imath -I $SRC/jxrlib/common/include -I $SRC/jxrlib/jxrgluelib -I $SRC/jxrlib/image/sys -I /usr/include/QtCore/ -I /usr/include/QtGui/ -I . $SRC/libavif/build/libavif.a /usr/local/lib/libheif.a /usr/local/lib/libde265.a /usr/local/lib/libopenh264.a $SRC/aom/build.libavif/libaom.a $SRC/libjxl/build/lib/libjxl_threads.a $SRC/libjxl/build/lib/libjxl.a $SRC/libjxl/build/lib/libjxl_cms.a $SRC/libjxl/build/third_party/highway/libhwy.a $SRC/libjxl/build/third_party/brotli/libbrotlidec.a $SRC/libjxl/build/third_party/brotli/libbrotlienc.a $SRC/libjxl/build/third_party/brotli/libbrotlicommon.a -lQt6Gui -lQt6Core -lQt6BundledLibpng -lQt6BundledHarfbuzz -lm -lQt6BundledPcre2 -ldl -lpthread $LIB_FUZZING_ENGINE /usr/local/lib/libz.a /usr/local/lib/x86_64-linux-gnu/libKF6Archive.a /usr/local/lib/libz.a /usr/local/lib/libraw.a /usr/local/lib/libOpenEXR-3_4.a /usr/local/lib/libIex-3_4.a /usr/local/lib/libImath-3_2.a /usr/local/lib/libIlmThread-3_4.a /usr/local/lib/libOpenEXRCore-3_4.a /usr/local/lib/libOpenEXRUtil-3_4.a /usr/local/lib/libopenjp2.a /usr/local/lib/libzstd.a $SRC/jxrlib/build/libjxrglue.a $SRC/jxrlib/build/libjpegxr.a /usr/local/lib/liblzma.a /usr/local/lib/libbz2.a -lclang_rt.builtins
 
   # -lclang_rt.builtins in the previous line is a temporary workaround to avoid a linker error "undefined reference to __truncsfhf2". Investigate why this is needed here, but not anywhere else, and possibly remove it.
 
   find . -name "*.${format}" | zip -q $OUT/${fuzz_target_name}_seed_corpus.zip -@
 )
 done
+
+# Manually add other supported extensions to HEIF seed corpus
+find . -type f \( -name "*.avci" -o -name "*.heic" -o -name "*.hej2" \) | zip -q $OUT/kimgio_heif_fuzzer_seed_corpus.zip -@
diff --git a/autotests/ossfuzz/kimgio_fuzzer.cc b/autotests/ossfuzz/kimgio_fuzzer.cc
index d0b033a..a3833c1 100644
--- a/autotests/ossfuzz/kimgio_fuzzer.cc
+++ b/autotests/ossfuzz/kimgio_fuzzer.cc
@@ -31,32 +31,87 @@
 #include <QImage>
 #include <QImageReader>
 
+#if defined KIMG_FUZZER_ani
 #include "ani_p.h"
+#define HANDLER ANIHandler
+#elif defined KIMG_FUZZER_avif
 #include "avif_p.h"
+#define HANDLER QAVIFHandler
+#elif defined KIMG_FUZZER_dds
 #include "dds_p.h"
+#define HANDLER QDDSHandler
+#elif defined KIMG_FUZZER_exr
 #include "exr_p.h"
+#define HANDLER EXRHandler
+#elif defined KIMG_FUZZER_ff
 #include "ff_p.h"
+#define HANDLER FFHandler
+#elif defined KIMG_FUZZER_hdr
 #include "hdr_p.h"
+#define HANDLER HDRHandler
+#elif defined KIMG_FUZZER_heif
 #include "heif_p.h"
+#define HANDLER HEIFHandler
+#elif defined KIMG_FUZZER_iff
 #include "iff_p.h"
+#define HANDLER IFFHandler
+#elif defined KIMG_FUZZER_jp2
 #include "jp2_p.h"
+#define HANDLER JP2Handler
+#elif defined KIMG_FUZZER_jxl
 #include "jxl_p.h"
+#define HANDLER QJpegXLHandler
+#elif defined KIMG_FUZZER_jxr
 #include "jxr_p.h"
+#define HANDLER JXRHandler
+#elif defined KIMG_FUZZER_kra
 #include "kra.h"
+#define HANDLER KraHandler
+#elif defined KIMG_FUZZER_ora
 #include "ora.h"
+#define HANDLER OraHandler
+#elif defined KIMG_FUZZER_pcx
 #include "pcx_p.h"
+#define HANDLER PCXHandler
+#elif defined KIMG_FUZZER_pfm
 #include "pfm_p.h"
+#define HANDLER PFMHandler
+#elif defined KIMG_FUZZER_pic
 #include "pic_p.h"
+#define HANDLER SoftimagePICHandler
+#elif defined KIMG_FUZZER_psd
 #include "psd_p.h"
+#define HANDLER PSDHandler
+#elif defined KIMG_FUZZER_pxr
 #include "pxr_p.h"
+#define HANDLER PXRHandler
+#elif defined KIMG_FUZZER_qoi
 #include "qoi_p.h"
+#define HANDLER QOIHandler
+#elif defined KIMG_FUZZER_ras
 #include "ras_p.h"
+#define HANDLER RASHandler
+#elif defined KIMG_FUZZER_raw
 #include "raw_p.h"
+#define HANDLER RAWHandler
+#elif defined KIMG_FUZZER_rgb
 #include "rgb_p.h"
+#define HANDLER RGBHandler
+#elif defined KIMG_FUZZER_sct
 #include "sct_p.h"
+#define HANDLER ScitexHandler
+#elif defined KIMG_FUZZER_tim
 #include "tim_p.h"
+#define HANDLER TIMHandler
+#elif defined KIMG_FUZZER_tga
 #include "tga_p.h"
+#define HANDLER TGAHandler
+#elif defined KIMG_FUZZER_xcf
 #include "xcf_p.h"
+#define HANDLER XCFHandler
+#else
+#error "KIMG_FUZZER_format not defined!"
+#endif
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 {
@@ -65,7 +120,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 
     QImageReader::setAllocationLimit(512);
 
-    QImageIOHandler* handler = new HANDLER();
+    QImageIOHandler *handler = new HANDLER();
 
     QImage i;
     QBuffer b;
diff --git a/autotests/ossfuzz/prepare_build.sh b/autotests/ossfuzz/prepare_build.sh
index 966d56b..b0bcdf5 100755
--- a/autotests/ossfuzz/prepare_build.sh
+++ b/autotests/ossfuzz/prepare_build.sh
@@ -27,8 +27,8 @@ apt-get update && \
 git clone --depth 1 https://github.com/madler/zlib.git
 git clone --depth 1 -b v1.5.7 https://github.com/facebook/zstd.git
 wget https://sourceware.org/pub/bzip2/bzip2-1.0.8.tar.gz
-git clone https://github.com/tukaani-project/xz.git
-git clone --depth 1 --branch=RB-3.3 https://github.com/AcademySoftwareFoundation/openexr.git
+git clone --depth 1 https://github.com/tukaani-project/xz.git
+git clone --depth 1 --branch=RB-3.4 https://github.com/AcademySoftwareFoundation/openexr.git
 git clone --depth 1 -b master https://invent.kde.org/frameworks/extra-cmake-modules.git
 git clone --depth 1 --branch=dev git://code.qt.io/qt/qtbase.git
 git clone --depth 1 --branch=dev git://code.qt.io/qt/qttools.git