diff --git a/BUILDING.md b/BUILDING.md
index 116d0dda..a119daab 100644
--- a/BUILDING.md
+++ b/BUILDING.md
@@ -409,7 +409,7 @@ iPhone 5S/iPad Mini 2/iPad Air and newer.
 
     IOS_PLATFORMDIR=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform
     IOS_SYSROOT=($IOS_PLATFORMDIR/Developer/SDKs/iPhoneOS*.sdk)
-    export CFLAGS="-Wall -arch arm64 -miphoneos-version-min=7.0 -funwind-tables"
+    export CFLAGS="-Wall -arch arm64 -miphoneos-version-min=8.0 -funwind-tables"
 
     cd {build_directory}
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index e2759e46..50d6490c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -203,6 +203,14 @@ if(ENABLE_SHARED)
   set(CMAKE_INSTALL_RPATH ${CMAKE_INSTALL_FULL_LIBDIR})
 endif()
 
+if(WITH_JPEG8 OR WITH_JPEG7)
+  set(WITH_ARITH_ENC 1)
+  set(WITH_ARITH_DEC 1)
+endif()
+if(WITH_JPEG8)
+  set(WITH_MEM_SRCDST 0)
+endif()
+
 if(WITH_12BIT)
   set(WITH_ARITH_DEC 0)
   set(WITH_ARITH_ENC 0)
@@ -215,14 +223,6 @@ else()
 endif()
 report_option(WITH_12BIT "12-bit JPEG support")
 
-if(WITH_JPEG8 OR WITH_JPEG7)
-  set(WITH_ARITH_ENC 1)
-  set(WITH_ARITH_DEC 1)
-endif()
-if(WITH_JPEG8)
-  set(WITH_MEM_SRCDST 0)
-endif()
-
 if(WITH_ARITH_DEC)
   set(D_ARITH_CODING_SUPPORTED 1)
 endif()
diff --git a/ChangeLog.md b/ChangeLog.md
index 8fb57a9c..f830aba6 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -160,6 +160,10 @@ toolchains targetting Arm64 (AArch64) Windows binaries.
 `jpeg_crop_scanline()` and interblock smoothing while decompressing only the DC
 scan of a progressive JPEG image.
 
+5. Fixed an issue whereby libjpeg-turbo would not build if 12-bit-per-component
+JPEG support (`WITH_12BIT`) was enabled along with libjpeg v7 or libjpeg v8
+API/ABI emulation (`WITH_JPEG7` or `WITH_JPEG8`.)
+
 
 2.0.5
 =====
diff --git a/jcinit.c b/jcinit.c
index 78aa4657..157353a2 100644
--- a/jcinit.c
+++ b/jcinit.c
@@ -1,8 +1,10 @@
 /*
  * jcinit.c
  *
+ * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1991-1997, Thomas G. Lane.
- * This file is part of the Independent JPEG Group's software.
+ * libjpeg-turbo Modifications:
+ * Copyright (C) 2020, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -19,6 +21,7 @@
 #define JPEG_INTERNALS
 #include "jinclude.h"
 #include "jpeglib.h"
+#include "jpegcomp.h"
 
 
 /*
diff --git a/jctrans.c b/jctrans.c
index ce70a309..ab6a2186 100644
--- a/jctrans.c
+++ b/jctrans.c
@@ -4,8 +4,8 @@
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1995-1998, Thomas G. Lane.
  * Modified 2000-2009 by Guido Vollbeding.
- * It was modified by The libjpeg-turbo Project to include only code relevant
- * to libjpeg-turbo.
+ * libjpeg-turbo Modifications:
+ * Copyright (C) 2020, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -17,6 +17,7 @@
 #define JPEG_INTERNALS
 #include "jinclude.h"
 #include "jpeglib.h"
+#include "jpegcomp.h"
 
 
 /* Forward declarations */
diff --git a/jdtrans.c b/jdtrans.c
index 56713efe..d7ec4b83 100644
--- a/jdtrans.c
+++ b/jdtrans.c
@@ -3,8 +3,8 @@
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1995-1997, Thomas G. Lane.
- * It was modified by The libjpeg-turbo Project to include only code relevant
- * to libjpeg-turbo.
+ * libjpeg-turbo Modifications:
+ * Copyright (C) 2020, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -16,6 +16,7 @@
 #define JPEG_INTERNALS
 #include "jinclude.h"
 #include "jpeglib.h"
+#include "jpegcomp.h"
 
 
 /* Forward declarations */
diff --git a/jpegcomp.h b/jpegcomp.h
index b32d544b..c4834ac0 100644
--- a/jpegcomp.h
+++ b/jpegcomp.h
@@ -1,7 +1,7 @@
 /*
  * jpegcomp.h
  *
- * Copyright (C) 2010, D. R. Commander.
+ * Copyright (C) 2010, 2020, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -19,6 +19,7 @@
 #define _min_DCT_v_scaled_size  min_DCT_v_scaled_size
 #define _jpeg_width  jpeg_width
 #define _jpeg_height  jpeg_height
+#define JERR_ARITH_NOTIMPL  JERR_NOT_COMPILED
 #else
 #define _DCT_scaled_size  DCT_scaled_size
 #define _DCT_h_scaled_size  DCT_scaled_size