diff --git a/src/MagnumPlugins/AnyImageConverter/AnyImageConverter.cpp b/src/MagnumPlugins/AnyImageConverter/AnyImageConverter.cpp
index 1a1ba784e..91e468a62 100644
--- a/src/MagnumPlugins/AnyImageConverter/AnyImageConverter.cpp
+++ b/src/MagnumPlugins/AnyImageConverter/AnyImageConverter.cpp
@@ -73,7 +73,8 @@ bool AnyImageConverter::doConvertToFile(const ImageView1D& image, const Containe
 
     /* Detect the plugin from extension */
     Containers::StringView plugin;
-    if(normalizedExtension == ".ktx2"_s)
+    if(normalizedExtension == ".ktx"_s ||
+       normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else {
         Error{} << "Trade::AnyImageConverter::convertToFile(): cannot determine the format of" << filename << "for a 1D image";
@@ -129,7 +130,8 @@ bool AnyImageConverter::doConvertToFile(const ImageView2D& image, const Containe
             normalizedExtension == ".jpeg"_s ||
             normalizedExtension == ".jpe"_s)
         plugin = "JpegImageConverter"_s;
-    else if(normalizedExtension == ".ktx2"_s)
+    else if(normalizedExtension == ".ktx"_s ||
+            normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else if(normalizedExtension == ".png"_s)
         plugin = "PngImageConverter"_s;
@@ -184,7 +186,8 @@ bool AnyImageConverter::doConvertToFile(const ImageView3D& image, const Containe
         plugin = "BasisImageConverter"_s;
     else if(normalizedExtension == ".exr"_s)
         plugin = "OpenExrImageConverter"_s;
-    else if(normalizedExtension == ".ktx2"_s)
+    else if(normalizedExtension == ".ktx"_s ||
+            normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else if(normalizedExtension == ".vdb"_s)
         plugin = "OpenVdbImageConverter"_s;
@@ -230,7 +233,8 @@ bool AnyImageConverter::doConvertToFile(const CompressedImageView1D& image, cons
 
     /* Detect the plugin from extension */
     Containers::StringView plugin;
-    if(normalizedExtension == ".ktx2"_s)
+    if(normalizedExtension == ".ktx"_s ||
+       normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else {
         Error{} << "Trade::AnyImageConverter::convertToFile(): cannot determine the format of" << filename << "for a compressed 1D image";
@@ -274,7 +278,8 @@ bool AnyImageConverter::doConvertToFile(const CompressedImageView2D& image, cons
 
     /* Detect the plugin from extension */
     Containers::StringView plugin;
-    if(normalizedExtension == ".ktx2"_s)
+    if(normalizedExtension == ".ktx"_s ||
+       normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else {
         Error{} << "Trade::AnyImageConverter::convertToFile(): cannot determine the format of" << filename << "for a compressed 2D image";
@@ -318,7 +323,8 @@ bool AnyImageConverter::doConvertToFile(const CompressedImageView3D& image, cons
 
     /* Detect the plugin from extension */
     Containers::StringView plugin;
-    if(normalizedExtension == ".ktx2"_s)
+    if(normalizedExtension == ".ktx"_s ||
+       normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else {
         Error{} << "Trade::AnyImageConverter::convertToFile(): cannot determine the format of" << filename << "for a compressed 3D image";
@@ -362,7 +368,8 @@ bool AnyImageConverter::doConvertToFile(const Containers::ArrayView<const ImageV
 
     /* Detect the plugin from extension */
     Containers::StringView plugin;
-    if(normalizedExtension == ".ktx2"_s)
+    if(normalizedExtension == ".ktx"_s ||
+       normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else {
         Error{} << "Trade::AnyImageConverter::convertToFile(): cannot determine the format of" << filename << "for a multi-level 1D image";
@@ -410,7 +417,8 @@ bool AnyImageConverter::doConvertToFile(const Containers::ArrayView<const ImageV
         plugin = "BasisImageConverter"_s;
     else if(normalizedExtension == ".exr"_s)
         plugin = "OpenExrImageConverter"_s;
-    else if(normalizedExtension == ".ktx2"_s)
+    else if(normalizedExtension == ".ktx"_s ||
+            normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else {
         Error{} << "Trade::AnyImageConverter::convertToFile(): cannot determine the format of" << filename << "for a multi-level 2D image";
@@ -458,7 +466,8 @@ bool AnyImageConverter::doConvertToFile(const Containers::ArrayView<const ImageV
         plugin = "BasisImageConverter"_s;
     else if(normalizedExtension == ".exr"_s)
         plugin = "OpenExrImageConverter"_s;
-    else if(normalizedExtension == ".ktx2"_s)
+    else if(normalizedExtension == ".ktx"_s ||
+            normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else {
         Error{} << "Trade::AnyImageConverter::convertToFile(): cannot determine the format of" << filename << "for a multi-level 3D image";
@@ -502,7 +511,8 @@ bool AnyImageConverter::doConvertToFile(const Containers::ArrayView<const Compre
 
     /* Detect the plugin from extension */
     Containers::StringView plugin;
-    if(normalizedExtension == ".ktx2"_s)
+    if(normalizedExtension == ".ktx"_s ||
+       normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else {
         Error{} << "Trade::AnyImageConverter::convertToFile(): cannot determine the format of" << filename << "for a multi-level compressed 1D image";
@@ -546,7 +556,8 @@ bool AnyImageConverter::doConvertToFile(const Containers::ArrayView<const Compre
 
     /* Detect the plugin from extension */
     Containers::StringView plugin;
-    if(normalizedExtension == ".ktx2"_s)
+    if(normalizedExtension == ".ktx"_s ||
+       normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else {
         Error{} << "Trade::AnyImageConverter::convertToFile(): cannot determine the format of" << filename << "for a multi-level compressed 2D image";
@@ -590,7 +601,8 @@ bool AnyImageConverter::doConvertToFile(const Containers::ArrayView<const Compre
 
     /* Detect the plugin from extension */
     Containers::StringView plugin;
-    if(normalizedExtension == ".ktx2"_s)
+    if(normalizedExtension == ".ktx"_s ||
+       normalizedExtension == ".ktx2"_s)
         plugin = "KtxImageConverter"_s;
     else {
         Error{} << "Trade::AnyImageConverter::convertToFile(): cannot determine the format of" << filename << "for a multi-level compressed 3D image";
diff --git a/src/MagnumPlugins/AnyImageConverter/AnyImageConverter.h b/src/MagnumPlugins/AnyImageConverter/AnyImageConverter.h
index 782690e3a..291d77815 100644
--- a/src/MagnumPlugins/AnyImageConverter/AnyImageConverter.h
+++ b/src/MagnumPlugins/AnyImageConverter/AnyImageConverter.h
@@ -68,9 +68,9 @@ tries to convert the file with it. Supported formats for uncompressed data:
     `HdrImageConverter`. Only uncompressed 2D images.
 -   JPEG (`*.jpg`, `*.jpe`, `*.jpeg`), converted with @ref JpegImageConverter
     or any other plugin that provides it. Only uncompressed 2D images.
--   KTX2 (`*.ktx2`), converted with @ref KtxImageConverter or any other plugin
-    that provides it. Uncompressed, compressed, 1D/2D/3D and multi-level
-    1D/2D/3D images.
+-   KTX1 and KTX2 (`*.ktx`, `*.ktx2`), converted with @ref KtxImageConverter or
+    any other plugin that provides it. Uncompressed, compressed, 1D/2D/3D and
+    multi-level 1D/2D/3D images.
 -   Portable Network Graphics (`*.png`), converted with @ref PngImageConverter
     or any other plugin that provides it. Only uncompressed 2D images.
 -   Truevision TGA (`*.tga`, `*.vda`, `*.icb`, `*.vst`), converted with
diff --git a/src/MagnumPlugins/AnyImageConverter/Test/AnyImageConverterTest.cpp b/src/MagnumPlugins/AnyImageConverter/Test/AnyImageConverterTest.cpp
index 367e285f4..4c8d6ee7a 100644
--- a/src/MagnumPlugins/AnyImageConverter/Test/AnyImageConverterTest.cpp
+++ b/src/MagnumPlugins/AnyImageConverter/Test/AnyImageConverterTest.cpp
@@ -141,6 +141,7 @@ constexpr struct {
     const char* filename;
     const char* plugin;
 } Detect1DData[]{
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     /* Have at least one test case with uppercase */
     {"KTX2 uppercase", "FIL~1.KTX2", "KtxImageConverter"}
@@ -159,6 +160,7 @@ constexpr struct {
     {"JPEG weird extension", "file.jpe", "JpegImageConverter"},
     /* Have at least one test case with uppercase */
     {"JPEG uppercase", "output.JPG", "JpegImageConverter"},
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "foo.ktx2", "KtxImageConverter"},
     {"PNG", "file.png", "PngImageConverter"}
 };
@@ -170,6 +172,7 @@ constexpr struct {
 } Detect3DData[]{
     {"Basis Universal", "file.basis", "BasisImageConverter"},
     {"EXR", "file.exr", "OpenExrImageConverter"},
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     {"OpenVDB", "volume.vdb", "OpenVdbImageConverter"},
     /* Have at least one test case with uppercase */
@@ -181,6 +184,7 @@ constexpr struct {
     const char* filename;
     const char* plugin;
 } DetectLevels1DData[]{
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     /* Have at least one test case with uppercase */
     {"KTX2 uppercase", "FIL~1.KTX2", "KtxImageConverter"}
@@ -193,6 +197,7 @@ constexpr struct {
 } DetectLevels2DData[]{
     {"Basis Universal", "file.basis", "BasisImageConverter"},
     {"EXR", "file.exr", "OpenExrImageConverter"},
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     /* Have at least one test case with uppercase */
     {"EXR uppercase", "FIL~1.EXR", "OpenExrImageConverter"}
@@ -205,6 +210,7 @@ constexpr struct {
 } DetectLevels3DData[]{
     {"Basis Universal", "file.basis", "BasisImageConverter"},
     {"EXR", "file.exr", "OpenExrImageConverter"},
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     /* Have at least one test case with uppercase */
     {"EXR uppercase", "FIL~1.EXR", "OpenExrImageConverter"}
@@ -218,6 +224,7 @@ constexpr struct {
     const char* filename;
     const char* plugin;
 } DetectCompressed1DData[]{
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     /* Have at least one test case with uppercase */
     {"KTX2 uppercase", "FIL~1.KTX2", "KtxImageConverter"}
@@ -228,6 +235,7 @@ constexpr struct {
     const char* filename;
     const char* plugin;
 } DetectCompressed2DData[]{
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     /* Have at least one test case with uppercase */
     {"KTX2 uppercase", "FIL~1.KTX2", "KtxImageConverter"}
@@ -238,6 +246,7 @@ constexpr struct {
     const char* filename;
     const char* plugin;
 } DetectCompressed3DData[]{
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     /* Have at least one test case with uppercase */
     {"KTX2 uppercase", "FIL~1.KTX2", "KtxImageConverter"}
@@ -248,6 +257,7 @@ constexpr struct {
     const char* filename;
     const char* plugin;
 } DetectCompressedLevels1DData[]{
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     /* Have at least one test case with uppercase */
     {"KTX2 uppercase", "FIL~1.KTX2", "KtxImageConverter"}
@@ -258,6 +268,7 @@ constexpr struct {
     const char* filename;
     const char* plugin;
 } DetectCompressedLevels2DData[]{
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     /* Have at least one test case with uppercase */
     {"KTX2 uppercase", "FIL~1.KTX2", "KtxImageConverter"}
@@ -268,6 +279,7 @@ constexpr struct {
     const char* filename;
     const char* plugin;
 } DetectCompressedLevels3DData[]{
+    {"KTX1", "file.ktx", "KtxImageConverter"},
     {"KTX2", "file.ktx2", "KtxImageConverter"},
     /* Have at least one test case with uppercase */
     {"KTX2 uppercase", "FIL~1.KTX2", "KtxImageConverter"}
diff --git a/src/MagnumPlugins/AnyImageImporter/AnyImageImporter.cpp b/src/MagnumPlugins/AnyImageImporter/AnyImageImporter.cpp
index 2c555b3d0..06a3e4485 100644
--- a/src/MagnumPlugins/AnyImageImporter/AnyImageImporter.cpp
+++ b/src/MagnumPlugins/AnyImageImporter/AnyImageImporter.cpp
@@ -94,7 +94,8 @@ void AnyImageImporter::doOpenFile(const Containers::StringView filename) {
         plugin = "JpegImporter"_s;
     else if(normalizedExtension == ".jp2"_s)
         plugin = "Jpeg2000Importer"_s;
-    else if(normalizedExtension == ".ktx2"_s)
+    else if(normalizedExtension == ".ktx"_s ||
+            normalizedExtension == ".ktx2"_s)
         plugin = "KtxImporter"_s;
     else if(normalizedExtension == ".mng"_s)
         plugin = "MngImporter"_s;
@@ -199,8 +200,10 @@ void AnyImageImporter::doOpenData(Containers::Array<char>&& data, DataFlags) {
     /* https://en.wikipedia.org/wiki/JPEG#Syntax_and_structure */
     else if(dataString.hasPrefix("\xff\xd8\xff"_s))
         plugin = "JpegImporter"_s;
-    /* https://github.khronos.org/KTX-Specification/#_identifier */
-    else if(dataString.hasPrefix("\xabKTX 20\xbb\r\n\x1a\n"_s))
+    /* https://github.khronos.org/KTX-Specification/#_identifier and
+       https://www.khronos.org/registry/KTX/specs/1.0/ktxspec_v1.html */
+    else if(dataString.hasPrefix("\xabKTX 20\xbb\r\n\x1a\n"_s) ||
+            dataString.hasPrefix("\xabKTX 11\xbb\r\n\x1a\n"_s))
         plugin = "KtxImporter"_s;
     /* https://en.wikipedia.org/wiki/Portable_Network_Graphics#File_header */
     else if(dataString.hasPrefix("\x89PNG\x0d\x0a\x1a\x0a"_s))
diff --git a/src/MagnumPlugins/AnyImageImporter/AnyImageImporter.h b/src/MagnumPlugins/AnyImageImporter/AnyImageImporter.h
index 1878e6eb1..9e1406142 100644
--- a/src/MagnumPlugins/AnyImageImporter/AnyImageImporter.h
+++ b/src/MagnumPlugins/AnyImageImporter/AnyImageImporter.h
@@ -78,8 +78,8 @@ Supported formats:
     loaded with @ref JpegImporter or any other plugin that provides it
 -   JPEG 2000 (`*.jp2`), loaded with any plugin that provides
     `Jpeg2000Importer`
--   KTX2 (`*.ktx2` or data with corresponding signature), loaded with
-    @ref KtxImporter or any other plugin that provides it
+-   KTX and KTX2 (`*.ktx`, `*.ktx2` or data with corresponding signature),
+    loaded with @ref KtxImporter or any other plugin that provides it
 -   Multiple-image Network Graphics (`*.mng`), loaded with any plugin that
     provides `MngImporter`
 -   Portable Bitmap (`*.pbm`), loaded with any plugin that provides `PbmImporter`
diff --git a/src/MagnumPlugins/AnyImageImporter/Test/AnyImageImporterTest.cpp b/src/MagnumPlugins/AnyImageImporter/Test/AnyImageImporterTest.cpp
index 93e8a73e3..047ea057a 100644
--- a/src/MagnumPlugins/AnyImageImporter/Test/AnyImageImporterTest.cpp
+++ b/src/MagnumPlugins/AnyImageImporter/Test/AnyImageImporterTest.cpp
@@ -110,6 +110,8 @@ constexpr struct {
     {"JPEG data", "gray.jpg", true, "JpegImporter"},
     {"JPEG uppercase", "uppercase.JPG", false, "JpegImporter"},
     {"JPEG2000", "image.jp2", false, "Jpeg2000Importer"},
+    {"KTX1", "version1.ktx", false, "KtxImporter"},
+    {"KTX1 data", "version1.ktx", true, "KtxImporter"},
     {"HDR", "rgb.hdr", false, "HdrImporter"},
     {"HDR data", "rgb.hdr", true, "HdrImporter"},
     {"ICO", "pngs.ico", false, "IcoImporter"},
diff --git a/src/MagnumPlugins/AnyImageImporter/Test/CMakeLists.txt b/src/MagnumPlugins/AnyImageImporter/Test/CMakeLists.txt
index 9638be446..b77a3f438 100644
--- a/src/MagnumPlugins/AnyImageImporter/Test/CMakeLists.txt
+++ b/src/MagnumPlugins/AnyImageImporter/Test/CMakeLists.txt
@@ -68,6 +68,8 @@ corrade_add_test(AnyImageImporterTest AnyImageImporterTest.cpp
         # Generated by AnyImageConverterTest::convert{1D,3D}()
         1d.ktx2
         3d.ktx2
+        # From KtxImporter test data (in magnum-plugins)
+        version1.ktx
         gray.jpg
         image.exr
         image.tiff
diff --git a/src/MagnumPlugins/AnyImageImporter/Test/version1.ktx b/src/MagnumPlugins/AnyImageImporter/Test/version1.ktx
new file mode 100644
index 000000000..d8ce8e4de
Binary files /dev/null and b/src/MagnumPlugins/AnyImageImporter/Test/version1.ktx differ