diff --git a/ChangeLog.txt b/ChangeLog.txt
index ecba1087..be51d288 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -5,6 +5,17 @@
 the application was invoked using I/O redirection
 (jpegtran <input.jpg >output.jpg).
 
+[2] The inclusion of libjpeg v7 and v8 emulation as well as arithmetic coding
+support in libjpeg-turbo v1.1.0 introduced several new error constants in
+jerror.h, and these were mistakenly enabled for all emulation modes, causing
+the error enum in libjpeg-turbo to have different values than the same enum in
+libjpeg.  This represents an ABI incompatibility, and it caused problems with
+applications that took specific action based on libjpeg error values.  The fix
+was to include the new error constants conditionally based on whether libjpeg
+v7 or v8 emulation or arithmetic coding support was enabled.  Note that to
+achieve full ABI compatibility with jpeg-6b, it is necessary to build
+libjpeg-turbo without arithmetic coding support.
+
 
 1.1.1
 =====
diff --git a/jerror.h b/jerror.h
index 88f019e8..0f10f0e9 100644
--- a/jerror.h
+++ b/jerror.h
@@ -40,15 +40,23 @@ typedef enum {
 JMESSAGE(JMSG_NOMESSAGE, "Bogus message code %d") /* Must be first entry! */
 
 /* For maintenance convenience, list is alphabetical by message code name */
+#if JPEG_LIB_VERSION < 70
 JMESSAGE(JERR_ARITH_NOTIMPL,
 	 "Sorry, arithmetic coding is not implemented")
+#endif
 JMESSAGE(JERR_BAD_ALIGN_TYPE, "ALIGN_TYPE is wrong, please fix")
 JMESSAGE(JERR_BAD_ALLOC_CHUNK, "MAX_ALLOC_CHUNK is wrong, please fix")
 JMESSAGE(JERR_BAD_BUFFER_MODE, "Bogus buffer control mode")
 JMESSAGE(JERR_BAD_COMPONENT_ID, "Invalid component ID %d in SOS")
+#if JPEG_LIB_VERSION >= 70
 JMESSAGE(JERR_BAD_CROP_SPEC, "Invalid crop request")
+#endif
 JMESSAGE(JERR_BAD_DCT_COEF, "DCT coefficient out of range")
 JMESSAGE(JERR_BAD_DCTSIZE, "IDCT output block size %d not supported")
+#if JPEG_LIB_VERSION >= 70
+JMESSAGE(JERR_BAD_DROP_SAMPLING,
+	 "Component index %d: mismatching sampling ratio %d:%d, %d:%d, %c")
+#endif
 JMESSAGE(JERR_BAD_HUFF_TABLE, "Bogus Huffman table definition")
 JMESSAGE(JERR_BAD_IN_COLORSPACE, "Bogus input colorspace")
 JMESSAGE(JERR_BAD_J_COLORSPACE, "Bogus JPEG colorspace")
@@ -95,7 +103,9 @@ JMESSAGE(JERR_MISSING_DATA, "Scan script does not transmit all data")
 JMESSAGE(JERR_MODE_CHANGE, "Invalid color quantization mode change")
 JMESSAGE(JERR_NOTIMPL, "Not implemented yet")
 JMESSAGE(JERR_NOT_COMPILED, "Requested feature was omitted at compile time")
+#if defined(C_ARITH_CODING_SUPPORTED) || defined(D_ARITH_CODING_SUPPORTED) || JPEG_LIB_VERSION >= 70
 JMESSAGE(JERR_NO_ARITH_TABLE, "Arithmetic table 0x%02x was not defined")
+#endif
 JMESSAGE(JERR_NO_BACKING_STORE, "Backing store not supported")
 JMESSAGE(JERR_NO_HUFF_TABLE, "Huffman table 0x%02x was not defined")
 JMESSAGE(JERR_NO_IMAGE, "JPEG datastream contains no image")
@@ -173,7 +183,9 @@ JMESSAGE(JTRC_UNKNOWN_IDS,
 JMESSAGE(JTRC_XMS_CLOSE, "Freed XMS handle %u")
 JMESSAGE(JTRC_XMS_OPEN, "Obtained XMS handle %u")
 JMESSAGE(JWRN_ADOBE_XFORM, "Unknown Adobe color transform code %d")
+#if defined(C_ARITH_CODING_SUPPORTED) || defined(D_ARITH_CODING_SUPPORTED) || JPEG_LIB_VERSION >= 70
 JMESSAGE(JWRN_ARITH_BAD_CODE, "Corrupt JPEG data: bad arithmetic code")
+#endif
 JMESSAGE(JWRN_BOGUS_PROGRESSION,
 	 "Inconsistent progression sequence for component %d coefficient %d")
 JMESSAGE(JWRN_EXTRANEOUS_DATA,
@@ -186,6 +198,9 @@ JMESSAGE(JWRN_MUST_RESYNC,
 	 "Corrupt JPEG data: found marker 0x%02x instead of RST%d")
 JMESSAGE(JWRN_NOT_SEQUENTIAL, "Invalid SOS parameters for sequential JPEG")
 JMESSAGE(JWRN_TOO_MUCH_DATA, "Application transferred too many scanlines")
+#if JPEG_LIB_VERSION < 70
+JMESSAGE(JERR_BAD_CROP_SPEC, "Invalid crop request")
+#endif
 
 #ifdef JMAKE_ENUM_LIST