diff --git a/src/decode.c b/src/decode.c
index 51d0aced2..00ecf555d 100644
--- a/src/decode.c
+++ b/src/decode.c
@@ -800,74 +800,6 @@ PyImaging_ZipDecoderNew(PyObject *self, PyObject *args) {
 }
 #endif
 
-/* -------------------------------------------------------------------- */
-/* JPEG                                                                 */
-/* -------------------------------------------------------------------- */
-
-#ifdef HAVE_LIBJPEG
-
-/* We better define this decoder last in this file, so the following
-   undef's won't mess things up for the Imaging library proper. */
-
-#undef HAVE_PROTOTYPES
-#undef HAVE_STDDEF_H
-#undef HAVE_STDLIB_H
-#undef UINT8
-#undef UINT16
-#undef UINT32
-#undef INT8
-#undef INT16
-#undef INT32
-
-#include "libImaging/Jpeg.h"
-
-PyObject *
-PyImaging_JpegDecoderNew(PyObject *self, PyObject *args) {
-    ImagingDecoderObject *decoder;
-
-    char *mode;
-    char *rawmode;  /* what we want from the decoder */
-    char *jpegmode; /* what's in the file */
-    int scale = 1;
-    int draft = 0;
-
-    if (!PyArg_ParseTuple(args, "ssz|ii", &mode, &rawmode, &jpegmode, &scale, &draft)) {
-        return NULL;
-    }
-
-    if (!jpegmode) {
-        jpegmode = "";
-    }
-
-    decoder = PyImaging_DecoderNew(sizeof(JPEGSTATE));
-    if (decoder == NULL) {
-        return NULL;
-    }
-
-    // libjpeg-turbo supports different output formats.
-    // We are choosing Pillow's native format (3 color bytes + 1 padding)
-    // to avoid extra conversion in Unpack.c.
-    if (ImagingJpegUseJCSExtensions() && strcmp(rawmode, "RGB") == 0) {
-        rawmode = "RGBX";
-    }
-
-    if (get_unpacker(decoder, mode, rawmode) < 0) {
-        return NULL;
-    }
-
-    decoder->decode = ImagingJpegDecode;
-    decoder->cleanup = ImagingJpegDecodeCleanup;
-
-    strncpy(((JPEGSTATE *)decoder->state.context)->rawmode, rawmode, 8);
-    strncpy(((JPEGSTATE *)decoder->state.context)->jpegmode, jpegmode, 8);
-
-    ((JPEGSTATE *)decoder->state.context)->scale = scale;
-    ((JPEGSTATE *)decoder->state.context)->draft = draft;
-
-    return (PyObject *)decoder;
-}
-#endif
-
 /* -------------------------------------------------------------------- */
 /* JPEG 2000                                                            */
 /* -------------------------------------------------------------------- */
@@ -925,3 +857,61 @@ PyImaging_Jpeg2KDecoderNew(PyObject *self, PyObject *args) {
     return (PyObject *)decoder;
 }
 #endif /* HAVE_OPENJPEG */
+
+/* -------------------------------------------------------------------- */
+/* JPEG                                                                 */
+/* -------------------------------------------------------------------- */
+
+#ifdef HAVE_LIBJPEG
+
+/* We better define this decoder last in this file, so the undef's
+   in Jpeg.h won't mess things up for the Imaging library proper. */
+
+#include "libImaging/Jpeg.h"
+
+PyObject *
+PyImaging_JpegDecoderNew(PyObject *self, PyObject *args) {
+    ImagingDecoderObject *decoder;
+
+    char *mode;
+    char *rawmode;  /* what we want from the decoder */
+    char *jpegmode; /* what's in the file */
+    int scale = 1;
+    int draft = 0;
+
+    if (!PyArg_ParseTuple(args, "ssz|ii", &mode, &rawmode, &jpegmode, &scale, &draft)) {
+        return NULL;
+    }
+
+    if (!jpegmode) {
+        jpegmode = "";
+    }
+
+    decoder = PyImaging_DecoderNew(sizeof(JPEGSTATE));
+    if (decoder == NULL) {
+        return NULL;
+    }
+
+    // libjpeg-turbo supports different output formats.
+    // We are choosing Pillow's native format (3 color bytes + 1 padding)
+    // to avoid extra conversion in Unpack.c.
+    if (ImagingJpegUseJCSExtensions() && strcmp(rawmode, "RGB") == 0) {
+        rawmode = "RGBX";
+    }
+
+    if (get_unpacker(decoder, mode, rawmode) < 0) {
+        return NULL;
+    }
+
+    decoder->decode = ImagingJpegDecode;
+    decoder->cleanup = ImagingJpegDecodeCleanup;
+
+    strncpy(((JPEGSTATE *)decoder->state.context)->rawmode, rawmode, 8);
+    strncpy(((JPEGSTATE *)decoder->state.context)->jpegmode, jpegmode, 8);
+
+    ((JPEGSTATE *)decoder->state.context)->scale = scale;
+    ((JPEGSTATE *)decoder->state.context)->draft = draft;
+
+    return (PyObject *)decoder;
+}
+#endif
diff --git a/src/encode.c b/src/encode.c
index 1a4cd489d..fa6c3a51c 100644
--- a/src/encode.c
+++ b/src/encode.c
@@ -982,24 +982,213 @@ PyImaging_LibTiffEncoderNew(PyObject *self, PyObject *args) {
 
 #endif
 
+/* -------------------------------------------------------------------- */
+/* JPEG 2000                                                            */
+/* -------------------------------------------------------------------- */
+
+#ifdef HAVE_OPENJPEG
+
+#include "libImaging/Jpeg2K.h"
+
+static void
+j2k_decode_coord_tuple(PyObject *tuple, int *x, int *y) {
+    *x = *y = 0;
+
+    if (tuple && PyTuple_Check(tuple) && PyTuple_GET_SIZE(tuple) == 2) {
+        *x = (int)PyLong_AsLong(PyTuple_GET_ITEM(tuple, 0));
+        *y = (int)PyLong_AsLong(PyTuple_GET_ITEM(tuple, 1));
+
+        if (*x < 0) {
+            *x = 0;
+        }
+        if (*y < 0) {
+            *y = 0;
+        }
+    }
+}
+
+PyObject *
+PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
+    ImagingEncoderObject *encoder;
+    JPEG2KENCODESTATE *context;
+
+    char *mode;
+    char *format;
+    OPJ_CODEC_FORMAT codec_format;
+    PyObject *offset = NULL, *tile_offset = NULL, *tile_size = NULL;
+    char *quality_mode = "rates";
+    PyObject *quality_layers = NULL;
+    Py_ssize_t num_resolutions = 0;
+    PyObject *cblk_size = NULL, *precinct_size = NULL;
+    PyObject *irreversible = NULL;
+    char *progression = "LRCP";
+    OPJ_PROG_ORDER prog_order;
+    char *cinema_mode = "no";
+    OPJ_CINEMA_MODE cine_mode;
+    char mct = 0;
+    int sgnd = 0;
+    Py_ssize_t fd = -1;
+    char *comment;
+    Py_ssize_t comment_size;
+    int plt = 0;
+
+    if (!PyArg_ParseTuple(
+            args,
+            "ss|OOOsOnOOOssbbnz#p",
+            &mode,
+            &format,
+            &offset,
+            &tile_offset,
+            &tile_size,
+            &quality_mode,
+            &quality_layers,
+            &num_resolutions,
+            &cblk_size,
+            &precinct_size,
+            &irreversible,
+            &progression,
+            &cinema_mode,
+            &mct,
+            &sgnd,
+            &fd,
+            &comment,
+            &comment_size,
+            &plt
+        )) {
+        return NULL;
+    }
+
+    if (strcmp(format, "j2k") == 0) {
+        codec_format = OPJ_CODEC_J2K;
+    } else if (strcmp(format, "jpt") == 0) {
+        codec_format = OPJ_CODEC_JPT;
+    } else if (strcmp(format, "jp2") == 0) {
+        codec_format = OPJ_CODEC_JP2;
+    } else {
+        return NULL;
+    }
+
+    if (strcmp(progression, "LRCP") == 0) {
+        prog_order = OPJ_LRCP;
+    } else if (strcmp(progression, "RLCP") == 0) {
+        prog_order = OPJ_RLCP;
+    } else if (strcmp(progression, "RPCL") == 0) {
+        prog_order = OPJ_RPCL;
+    } else if (strcmp(progression, "PCRL") == 0) {
+        prog_order = OPJ_PCRL;
+    } else if (strcmp(progression, "CPRL") == 0) {
+        prog_order = OPJ_CPRL;
+    } else {
+        return NULL;
+    }
+
+    if (strcmp(cinema_mode, "no") == 0) {
+        cine_mode = OPJ_OFF;
+    } else if (strcmp(cinema_mode, "cinema2k-24") == 0) {
+        cine_mode = OPJ_CINEMA2K_24;
+    } else if (strcmp(cinema_mode, "cinema2k-48") == 0) {
+        cine_mode = OPJ_CINEMA2K_48;
+    } else if (strcmp(cinema_mode, "cinema4k-24") == 0) {
+        cine_mode = OPJ_CINEMA4K_24;
+    } else {
+        return NULL;
+    }
+
+    encoder = PyImaging_EncoderNew(sizeof(JPEG2KENCODESTATE));
+    if (!encoder) {
+        return NULL;
+    }
+
+    encoder->encode = ImagingJpeg2KEncode;
+    encoder->cleanup = ImagingJpeg2KEncodeCleanup;
+    encoder->pushes_fd = 1;
+
+    context = (JPEG2KENCODESTATE *)encoder->state.context;
+
+    context->fd = fd;
+    context->format = codec_format;
+    context->offset_x = context->offset_y = 0;
+
+    j2k_decode_coord_tuple(offset, &context->offset_x, &context->offset_y);
+    j2k_decode_coord_tuple(
+        tile_offset, &context->tile_offset_x, &context->tile_offset_y
+    );
+    j2k_decode_coord_tuple(tile_size, &context->tile_size_x, &context->tile_size_y);
+
+    /* Error on illegal tile offsets */
+    if (context->tile_size_x && context->tile_size_y) {
+        if (context->tile_offset_x <= context->offset_x - context->tile_size_x ||
+            context->tile_offset_y <= context->offset_y - context->tile_size_y) {
+            PyErr_SetString(
+                PyExc_ValueError,
+                "JPEG 2000 tile offset too small; top left tile must "
+                "intersect image area"
+            );
+            Py_DECREF(encoder);
+            return NULL;
+        }
+
+        if (context->tile_offset_x > context->offset_x ||
+            context->tile_offset_y > context->offset_y) {
+            PyErr_SetString(
+                PyExc_ValueError, "JPEG 2000 tile offset too large to cover image area"
+            );
+            Py_DECREF(encoder);
+            return NULL;
+        }
+    }
+
+    if (comment && comment_size > 0) {
+        /* Size is stored as as an uint16, subtract 4 bytes for the header */
+        if (comment_size >= 65532) {
+            PyErr_SetString(PyExc_ValueError, "JPEG 2000 comment is too long");
+            Py_DECREF(encoder);
+            return NULL;
+        }
+
+        char *p = malloc(comment_size + 1);
+        if (!p) {
+            Py_DECREF(encoder);
+            return ImagingError_MemoryError();
+        }
+        memcpy(p, comment, comment_size);
+        p[comment_size] = '\0';
+        context->comment = p;
+    }
+
+    if (quality_layers && PySequence_Check(quality_layers)) {
+        context->quality_is_in_db = strcmp(quality_mode, "dB") == 0;
+        context->quality_layers = quality_layers;
+        Py_INCREF(quality_layers);
+    }
+
+    context->num_resolutions = num_resolutions;
+
+    j2k_decode_coord_tuple(cblk_size, &context->cblk_width, &context->cblk_height);
+    j2k_decode_coord_tuple(
+        precinct_size, &context->precinct_width, &context->precinct_height
+    );
+
+    context->irreversible = PyObject_IsTrue(irreversible);
+    context->progression = prog_order;
+    context->cinema_mode = cine_mode;
+    context->mct = mct;
+    context->sgnd = sgnd;
+    context->plt = plt;
+
+    return (PyObject *)encoder;
+}
+
+#endif
+
 /* -------------------------------------------------------------------- */
 /* JPEG                                                                 */
 /* -------------------------------------------------------------------- */
 
 #ifdef HAVE_LIBJPEG
 
-/* We better define this encoder last in this file, so the following
-   undef's won't mess things up for the Imaging library proper. */
-
-#undef HAVE_PROTOTYPES
-#undef HAVE_STDDEF_H
-#undef HAVE_STDLIB_H
-#undef UINT8
-#undef UINT16
-#undef UINT32
-#undef INT8
-#undef INT16
-#undef INT32
+/* We better define this decoder last in this file, so the undef's
+   in Jpeg.h won't mess things up for the Imaging library proper. */
 
 #include "libImaging/Jpeg.h"
 
@@ -1212,202 +1401,3 @@ PyImaging_JpegEncoderNew(PyObject *self, PyObject *args) {
 }
 
 #endif
-
-/* -------------------------------------------------------------------- */
-/* JPEG 2000                                                            */
-/* -------------------------------------------------------------------- */
-
-#ifdef HAVE_OPENJPEG
-
-#include "libImaging/Jpeg2K.h"
-
-static void
-j2k_decode_coord_tuple(PyObject *tuple, int *x, int *y) {
-    *x = *y = 0;
-
-    if (tuple && PyTuple_Check(tuple) && PyTuple_GET_SIZE(tuple) == 2) {
-        *x = (int)PyLong_AsLong(PyTuple_GET_ITEM(tuple, 0));
-        *y = (int)PyLong_AsLong(PyTuple_GET_ITEM(tuple, 1));
-
-        if (*x < 0) {
-            *x = 0;
-        }
-        if (*y < 0) {
-            *y = 0;
-        }
-    }
-}
-
-PyObject *
-PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
-    ImagingEncoderObject *encoder;
-    JPEG2KENCODESTATE *context;
-
-    char *mode;
-    char *format;
-    OPJ_CODEC_FORMAT codec_format;
-    PyObject *offset = NULL, *tile_offset = NULL, *tile_size = NULL;
-    char *quality_mode = "rates";
-    PyObject *quality_layers = NULL;
-    Py_ssize_t num_resolutions = 0;
-    PyObject *cblk_size = NULL, *precinct_size = NULL;
-    PyObject *irreversible = NULL;
-    char *progression = "LRCP";
-    OPJ_PROG_ORDER prog_order;
-    char *cinema_mode = "no";
-    OPJ_CINEMA_MODE cine_mode;
-    char mct = 0;
-    int sgnd = 0;
-    Py_ssize_t fd = -1;
-    char *comment;
-    Py_ssize_t comment_size;
-    int plt = 0;
-
-    if (!PyArg_ParseTuple(
-            args,
-            "ss|OOOsOnOOOssbbnz#p",
-            &mode,
-            &format,
-            &offset,
-            &tile_offset,
-            &tile_size,
-            &quality_mode,
-            &quality_layers,
-            &num_resolutions,
-            &cblk_size,
-            &precinct_size,
-            &irreversible,
-            &progression,
-            &cinema_mode,
-            &mct,
-            &sgnd,
-            &fd,
-            &comment,
-            &comment_size,
-            &plt
-        )) {
-        return NULL;
-    }
-
-    if (strcmp(format, "j2k") == 0) {
-        codec_format = OPJ_CODEC_J2K;
-    } else if (strcmp(format, "jpt") == 0) {
-        codec_format = OPJ_CODEC_JPT;
-    } else if (strcmp(format, "jp2") == 0) {
-        codec_format = OPJ_CODEC_JP2;
-    } else {
-        return NULL;
-    }
-
-    if (strcmp(progression, "LRCP") == 0) {
-        prog_order = OPJ_LRCP;
-    } else if (strcmp(progression, "RLCP") == 0) {
-        prog_order = OPJ_RLCP;
-    } else if (strcmp(progression, "RPCL") == 0) {
-        prog_order = OPJ_RPCL;
-    } else if (strcmp(progression, "PCRL") == 0) {
-        prog_order = OPJ_PCRL;
-    } else if (strcmp(progression, "CPRL") == 0) {
-        prog_order = OPJ_CPRL;
-    } else {
-        return NULL;
-    }
-
-    if (strcmp(cinema_mode, "no") == 0) {
-        cine_mode = OPJ_OFF;
-    } else if (strcmp(cinema_mode, "cinema2k-24") == 0) {
-        cine_mode = OPJ_CINEMA2K_24;
-    } else if (strcmp(cinema_mode, "cinema2k-48") == 0) {
-        cine_mode = OPJ_CINEMA2K_48;
-    } else if (strcmp(cinema_mode, "cinema4k-24") == 0) {
-        cine_mode = OPJ_CINEMA4K_24;
-    } else {
-        return NULL;
-    }
-
-    encoder = PyImaging_EncoderNew(sizeof(JPEG2KENCODESTATE));
-    if (!encoder) {
-        return NULL;
-    }
-
-    encoder->encode = ImagingJpeg2KEncode;
-    encoder->cleanup = ImagingJpeg2KEncodeCleanup;
-    encoder->pushes_fd = 1;
-
-    context = (JPEG2KENCODESTATE *)encoder->state.context;
-
-    context->fd = fd;
-    context->format = codec_format;
-    context->offset_x = context->offset_y = 0;
-
-    j2k_decode_coord_tuple(offset, &context->offset_x, &context->offset_y);
-    j2k_decode_coord_tuple(
-        tile_offset, &context->tile_offset_x, &context->tile_offset_y
-    );
-    j2k_decode_coord_tuple(tile_size, &context->tile_size_x, &context->tile_size_y);
-
-    /* Error on illegal tile offsets */
-    if (context->tile_size_x && context->tile_size_y) {
-        if (context->tile_offset_x <= context->offset_x - context->tile_size_x ||
-            context->tile_offset_y <= context->offset_y - context->tile_size_y) {
-            PyErr_SetString(
-                PyExc_ValueError,
-                "JPEG 2000 tile offset too small; top left tile must "
-                "intersect image area"
-            );
-            Py_DECREF(encoder);
-            return NULL;
-        }
-
-        if (context->tile_offset_x > context->offset_x ||
-            context->tile_offset_y > context->offset_y) {
-            PyErr_SetString(
-                PyExc_ValueError, "JPEG 2000 tile offset too large to cover image area"
-            );
-            Py_DECREF(encoder);
-            return NULL;
-        }
-    }
-
-    if (comment && comment_size > 0) {
-        /* Size is stored as as an uint16, subtract 4 bytes for the header */
-        if (comment_size >= 65532) {
-            PyErr_SetString(PyExc_ValueError, "JPEG 2000 comment is too long");
-            Py_DECREF(encoder);
-            return NULL;
-        }
-
-        char *p = malloc(comment_size + 1);
-        if (!p) {
-            Py_DECREF(encoder);
-            return ImagingError_MemoryError();
-        }
-        memcpy(p, comment, comment_size);
-        p[comment_size] = '\0';
-        context->comment = p;
-    }
-
-    if (quality_layers && PySequence_Check(quality_layers)) {
-        context->quality_is_in_db = strcmp(quality_mode, "dB") == 0;
-        context->quality_layers = quality_layers;
-        Py_INCREF(quality_layers);
-    }
-
-    context->num_resolutions = num_resolutions;
-
-    j2k_decode_coord_tuple(cblk_size, &context->cblk_width, &context->cblk_height);
-    j2k_decode_coord_tuple(
-        precinct_size, &context->precinct_width, &context->precinct_height
-    );
-
-    context->irreversible = PyObject_IsTrue(irreversible);
-    context->progression = prog_order;
-    context->cinema_mode = cine_mode;
-    context->mct = mct;
-    context->sgnd = sgnd;
-    context->plt = plt;
-
-    return (PyObject *)encoder;
-}
-
-#endif
diff --git a/src/libImaging/Jpeg.h b/src/libImaging/Jpeg.h
index 7cdba9022..d4604f84f 100644
--- a/src/libImaging/Jpeg.h
+++ b/src/libImaging/Jpeg.h
@@ -8,7 +8,16 @@
  * Copyright (c) 1995-1996 by Fredrik Lundh
  */
 
-#include "jpeglib.h"
+/* This undefs ruquired for libjpeg v8 and below */
+
+#undef UINT8
+#undef UINT16
+#undef UINT32
+#undef INT8
+#undef INT16
+#undef INT32
+
+#include <jpeglib.h>
 
 #include <setjmp.h>
 
diff --git a/src/libImaging/JpegDecode.c b/src/libImaging/JpegDecode.c
index 2970f56d1..838a7483c 100644
--- a/src/libImaging/JpegDecode.c
+++ b/src/libImaging/JpegDecode.c
@@ -25,15 +25,6 @@
 
 #ifdef HAVE_LIBJPEG
 
-#undef HAVE_PROTOTYPES
-#undef HAVE_STDLIB_H
-#undef HAVE_STDDEF_H
-#undef UINT8
-#undef UINT16
-#undef UINT32
-#undef INT16
-#undef INT32
-
 #include "Jpeg.h"
 
 #define STRINGIFY(x) #x
diff --git a/src/libImaging/JpegEncode.c b/src/libImaging/JpegEncode.c
index 4372d51d5..880a31117 100644
--- a/src/libImaging/JpegEncode.c
+++ b/src/libImaging/JpegEncode.c
@@ -23,15 +23,6 @@
 
 #ifdef HAVE_LIBJPEG
 
-#undef HAVE_PROTOTYPES
-#undef HAVE_STDLIB_H
-#undef HAVE_STDDEF_H
-#undef UINT8
-#undef UINT16
-#undef UINT32
-#undef INT16
-#undef INT32
-
 #include "Jpeg.h"
 
 /* -------------------------------------------------------------------- */