diff --git a/configure.ac b/configure.ac
index 9697fbd..211e0e5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -555,40 +555,6 @@
 esac
 AM_CONDITIONAL([COND_THREADS], [test "x$enable_threads" != xno])
 
-# As a Debian-specific hack, liblzma can use dlopen() to check if extra
-# paranoia is needed because unversioned symbols from liblzma.so.2 are
-# present in the same process.  See src/liblzma/common/common.c.
-AC_MSG_CHECKING([if lzma_code checks should be relaxed for compatibility])
-AC_ARG_ENABLE([liblzma2-compat], [AC_HELP_STRING([--enable-liblzma2-compat],
-		[Relax run-time checks to accomodate old binaries built
-		with smaller sizeof(lzma_stream).  The default is "dynamic",
-		which means to only use the relaxed checks when the dynamic
-		loader reports that liblzma.so.2 is loaded in the same process.])],
-	[], [enable_liblzma2_compat=dynamic])
-case $enable_liblzma2_compat in
-dynamic)
-	AC_SEARCH_LIBS([dlopen], [dl])
-	AC_DEFINE([LIBLZMA2_COMPAT_DYNAMIC], [1],
-		[Define to 1 to use dlopen() to check if lzma_code() checks
-		should be more tolerant because the process is also linked to
-		liblzma from Debian 6.0.])
-	AC_MSG_RESULT([auto])
-	;;
-yes)
-	AC_DEFINE([LIBLZMA2_COMPAT], [1],
-		[Define to 1 to unconditionally make lzma_code() checks tolerant
-		to accomodate callers built against liblzma from Debian 6.0.])
-	AC_MSG_RESULT([yes])
-	;;
-no)
-	AC_MSG_RESULT([no])
-	;;
-*)
-	AC_MSG_RESULT([])
-	AC_MSG_ERROR([--enable-liblzma2: unrecognized value $enable_liblzma2_compat])
-	;;
-esac
-
 echo
 echo "Initializing Libtool:"
 LT_PREREQ([2.2])
diff --git a/debian/changelog b/debian/changelog
index 3649dd4..bd09238 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,16 @@
+xz-utils (5.2.2-1.4) unstable; urgency=low
+
+  * liblzma:
+    - Remove compatibility tricks that permit sharing a process with
+      liblzma.so.2.  This means liblzma.a no longer depends on libdl
+      at run time.
+      Closes: #919950.  Thanks to Josh Triplett.
+    - Breaks: liblzma2 versions without symbol versioning.
+  * xz-utils:
+    - README.Debian: Remove notes about liblzma.so.2 compatibility.
+
+ -- Jonathan Nieder <jrnieder@gmail.com>  Sun, 27 Jan 2019 15:02:13 -0800
+
 xz-utils (5.2.2-1.3) unstable; urgency=medium
 
   * Non-maintainer upload.
diff --git a/debian/control b/debian/control
index 7e91b73..1f61f53 100644
--- a/debian/control
+++ b/debian/control
@@ -18,6 +18,7 @@
 Architecture: any
 Depends: ${shlibs:Depends}, ${misc:Depends}
 Pre-Depends: ${misc:Pre-Depends}
+Breaks: liblzma2 (<< 5.1.1alpha+20110809-3~)
 Multi-Arch: same
 Description: XZ-format compression library
  XZ is the successor to the Lempel-Ziv/Markov-chain Algorithm
diff --git a/debian/patches/liblzma-make-dlopen-based-liblzma2-compatibility-opt.patch b/debian/patches/liblzma-make-dlopen-based-liblzma2-compatibility-opt.patch
deleted file mode 100644
index 54617d9..0000000
--- a/debian/patches/liblzma-make-dlopen-based-liblzma2-compatibility-opt.patch
+++ /dev/null
@@ -1,197 +0,0 @@
-From e284cfe27457239e932038fb90084c91f4229c36 Mon Sep 17 00:00:00 2001
-From: Jonathan Nieder <jrnieder@gmail.com>
-Date: Sat, 16 Jun 2012 05:57:42 -0500
-Subject: liblzma: make dlopen()-based liblzma2 compatibility optional
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-Suppose I want to build a statically linked program:
-
-	gcc -static -o app app.c -lrpm -llzma
-
-Suppose further that librpm.a was built against a pre-5.0 version of
-liblzma so it does not allocate as much space for reserved fields at
-the end of lzma_stream as the current API requires.
-
-(This is a hypothetical scenario --- Debian librpm does not provide a
-static library.)
-
-If liblzma uses unpatched lzma_code() from XZ Utils >= 5.0, then
-during calls to librpm that try to compress or decompress an
-xz-compressed RPM, lzma_code’s reserved field checks will overflow the
-buffer and segfault.
-
-If liblzma uses the modified version of lzma_code() which asks libdl
-if liblzma.so.2 is resident and refrains from checking reserved fields
-past the end of the old lzma_stream struct when the answer is "yes",
-the behavior is no better.  The dynamic library liblzma.so.2 is _not_
-resident, so lzma_code() dutifully reads reserved fields past the end
-of the buffer --- segfault.
-
-So the only safe behavior in the static library is to unconditionally
-disable checks that might break for callers we want to continue to
-support.
-
-The new "./configure --enable-liblzma2-compat" option implements all
-three sets of semantics:
-
- - "./configure --disable-liblzma2-compat" means to check the full set
-   of reserved fields unconditionally.  You can use this to check how
-   your application would behave with the unpatched library.
-
- - "./configure --enable-liblzma2-compat=auto" means to skip checks of
-   reserved fields past the old end of struct lzma_stream when
-   liblzma.so.2 is resident.  If a DSO built against liblzma2 shares
-   the process image, the ABI-incompatible checks are skipped for
-   safety, whereas in the usual case when no such DSO is resident, the
-   full set of checks is run to help application developers remember
-   to zero all reserved fields.
-
- - "./configure --enable-liblzma2-compat" makes liblzma skip the
-   ABI-incompatible checks unconditionallty.  You can use this if you
-   want your copy of liblzma to be usable by static libraries that
-   were built against the old library.
-
-Patch-Name: liblzma-make-dlopen-based-liblzma2-compatibility-opt.patch
-Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
----
- configure.ac                | 33 +++++++++++++++++++++++++++++++--
- src/liblzma/common/common.c | 40 +++++++++++++++++++++++++++++++++++-----
- src/liblzma/common/common.h |  2 ++
- 3 files changed, 68 insertions(+), 7 deletions(-)
-
-diff --git a/configure.ac b/configure.ac
-index 6dae0b9756d6..d17629e0e7f6 100644
---- a/configure.ac
-+++ b/configure.ac
-@@ -548,10 +548,39 @@ case $enable_threads in
- esac
- AM_CONDITIONAL([COND_THREADS], [test "x$enable_threads" != xno])
- 
--# As a Debian-specific hack, liblzma uses dlopen() to check if extra
-+# As a Debian-specific hack, liblzma can use dlopen() to check if extra
- # paranoia is needed because unversioned symbols from liblzma.so.2 are
- # present in the same process.  See src/liblzma/common/common.c.
--AC_SEARCH_LIBS([dlopen], [dl])
-+AC_MSG_CHECKING([if lzma_code checks should be relaxed for compatibility])
-+AC_ARG_ENABLE([liblzma2-compat], [AC_HELP_STRING([--enable-liblzma2-compat],
-+		[Relax run-time checks to accomodate old binaries built
-+		with smaller sizeof(lzma_stream).  The default is "dynamic",
-+		which means to only use the relaxed checks when the dynamic
-+		loader reports that liblzma.so.2 is loaded in the same process.])],
-+	[], [enable_liblzma2_compat=dynamic])
-+case $enable_liblzma2_compat in
-+dynamic)
-+	AC_SEARCH_LIBS([dlopen], [dl])
-+	AC_DEFINE([LIBLZMA2_COMPAT_DYNAMIC], [1],
-+		[Define to 1 to use dlopen() to check if lzma_code() checks
-+		should be more tolerant because the process is also linked to
-+		liblzma from Debian 6.0.])
-+	AC_MSG_RESULT([auto])
-+	;;
-+yes)
-+	AC_DEFINE([LIBLZMA2_COMPAT], [1],
-+		[Define to 1 to unconditionally make lzma_code() checks tolerant
-+		to accomodate callers built against liblzma from Debian 6.0.])
-+	AC_MSG_RESULT([yes])
-+	;;
-+no)
-+	AC_MSG_RESULT([no])
-+	;;
-+*)
-+	AC_MSG_RESULT([])
-+	AC_MSG_ERROR([--enable-liblzma2: unrecognized value $enable_liblzma2_compat])
-+	;;
-+esac
- 
- echo
- echo "Initializing Libtool:"
-diff --git a/src/liblzma/common/common.c b/src/liblzma/common/common.c
-index 5474211cf0ca..79427b005b4b 100644
---- a/src/liblzma/common/common.c
-+++ b/src/liblzma/common/common.c
-@@ -164,16 +164,46 @@ lzma_next_end(lzma_next_coder *next, const lzma_allocator *allocator)
- // External to internal API wrapper //
- //////////////////////////////////////
- 
--static bool
--liblzma2_loaded(void)
-+#ifdef LIBLZMA2_COMPAT_DYNAMIC
-+
-+static void
-+init_liblzma2_compat(lzma_stream *strm)
- {
- 	void *handle = dlopen("liblzma.so.2", RTLD_LAZY | RTLD_NOLOAD);
- 	if (handle) {
- 		dlclose(handle);
--		return true;
-+		strm->internal->liblzma2_compat = true;
-+		return;
- 	}
-+	strm->internal->liblzma2_compat = false;
-+}
-+
-+static bool
-+liblzma2_loaded(lzma_stream *strm)
-+{
-+	return strm->internal->liblzma2_compat;
-+}
-+
-+#else
-+
-+static void
-+init_liblzma2_compat(lzma_stream *strm)
-+{
-+}
-+
-+#ifdef LIBLZMA2_COMPAT
-+static bool liblzma2_loaded(lzma_stream *strm)
-+{
-+	return true;
-+}
-+#else
-+static bool liblzma2_loaded(lzma_stream *strm)
-+{
- 	return false;
- }
-+#endif
-+
-+#endif
- 
- extern lzma_ret
- lzma_strm_init(lzma_stream *strm)
-@@ -188,7 +218,7 @@ lzma_strm_init(lzma_stream *strm)
- 			return LZMA_MEM_ERROR;
- 
- 		strm->internal->next = LZMA_NEXT_CODER_INIT;
--		strm->internal->liblzma2_compat = liblzma2_loaded();
-+		init_liblzma2_compat(strm);
- 	}
- 
- 	memzero(strm->internal->supported_actions,
-@@ -241,7 +271,7 @@ lzma_code(lzma_stream *strm, lzma_action action)
- 			|| strm->reserved_ptr4 != NULL)
- 		return LZMA_OPTIONS_ERROR;
- 
--	if (strm->internal->liblzma2_compat)
-+	if (liblzma2_loaded(strm))
- 		; /* Enough checks. */
- 	else if (strm->reserved_int1 != 0
- 			|| strm->reserved_int2 != 0
-diff --git a/src/liblzma/common/common.h b/src/liblzma/common/common.h
-index b056e417a29e..eb1d0525c07d 100644
---- a/src/liblzma/common/common.h
-+++ b/src/liblzma/common/common.h
-@@ -227,9 +227,11 @@ struct lzma_internal_s {
- 	/// made (no input consumed and no output produced by next.code).
- 	bool allow_buf_error;
- 
-+#ifdef LIBLZMA2_COMPAT_DYNAMIC
- 	/// Indicates whether we are sharing a process image with
- 	/// liblzma.so.2 and need to tread carefully.
- 	bool liblzma2_compat;
-+#endif
- };
- 
- 
diff --git a/debian/patches/liblzma-skip-ABI-incompatible-check-when-liblzma.so.patch b/debian/patches/liblzma-skip-ABI-incompatible-check-when-liblzma.so.patch
deleted file mode 100644
index 066d260..0000000
--- a/debian/patches/liblzma-skip-ABI-incompatible-check-when-liblzma.so.patch
+++ /dev/null
@@ -1,211 +0,0 @@
-From 7e228a81c1aa330de9289f579f768c7c9a686db2 Mon Sep 17 00:00:00 2001
-From: Jonathan Nieder <jrnieder@gmail.com>
-Date: Thu, 17 May 2012 18:49:00 -0500
-Subject: liblzma: skip ABI-incompatible check when liblzma.so.2 is loaded
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-When liblzma started using ELF symbol versioning at the same time
-as a soname bump (2 → 5) and a small increase in the reserved space at
-the end of the lzma_stream structure checked by lzma_code, introducing
-an unversioned compatibility symbol to ease the transition seemed like
-a great idea.  After all:
-
- - most applications only use one version of the library (liblzma.so.2
-   or liblzma.so.5) and would obviously work fine
-
- - applications linking to the new version of the library
-   (liblzma.so.5) should use the default, versioned lzma_code symbol so
-   errors initializing the reserved space can be noticed
-
- - symbol versioning should ensure application/library mixtures
-   independently making use of both versions of the library also
-   work.  Calls using the unversioned symbol names would be resolved
-   using the old symbol from liblzma.so.2 or the compatibility symbol
-   from liblzma.so.5, avoiding segfaults and spurious
-   LZMA_OPTIONS_ERROR errors.
-
- - application/library mixtures using both versions of the library and
-   passing lzma_stream objects between the two would break, but that
-   was never supposed to be supported, anyway.
-
-Three toolchain bugs dash that plan.
-
-Current (2.22) versions of the gold linker cannot be used to build
-libraries providing versioned and unversioned symbols with the same
-name.  On the other hand, BFD ld doesn't mind.  So GNU gold refuses to
-link versions of liblzma including the compatibility symbol (PR12261):
-
-	/usr/bin/ld: error: symbol lzma_code has undefined version
-
-Annoying, but livable.  liblzma with the compatibility symbol just
-has to be built with BFD ld.
-
-More importantly, gold does not support linking to libraries providing
-versioned and unversioned symbols with the same name.  If I link some
-code to a version of liblzma with the compatibility symbol:
-
-	ld -o demo demo.o -llzma
-
-then the documented behavior, implemented by BFD ld, is to interpret
-calls to lzma_code as referring to the default version
-(lzma_code@XZ_5.0).  Current versions of GNU gold treat such calls as
-referring to whichever symbol comes first in liblzma.so.5's symbol
-table.  If the unversioned symbol comes first (and in Debian liblzma5
-5.1.1alpha+20110809-3 it does), GNU gold will mislink new applications
-to use the unversioned compatibility symbol (PR13521):
-
-	$ ld.gold -o test.gold test.o -llzma
-	$ eu-readelf -s test.gold | grep lzma_code
-	    1: 0000000000000000      0 FUNC    GLOBAL DEFAULT    UNDEF lzma_code
-	    5: 0000000000000000      0 FUNC    GLOBAL DEFAULT    UNDEF lzma_code
-
-There is no warning.
-
-Worse, ld.so from glibc unpredictably will sometimes use the versioned
-symbol to resolve references to the unversioned base version when both
-are present (PR12977).
-
-Clearly no one has been testing mixtures of versioned and
-unversioned symbols at all, and we cannot trust the symbol resolution
-process to do anything in particular for them.
-
-This patch implements an alternative method to implement the same
-compatibility goals described above.
-
- - No more compatibility symbol.  liblzma.so.5 will define lzma_code
-   only once, with version XZ_5.0.
-
- - When initializing an lzma_stream object, use dlopen("liblzma.so.2",
-   RTLD_NOLOAD) to detect whether the caller might have been expecting
-   the old ABI, and store that information in the private
-   stream->internal->liblzma2_compat field.
-
- - In lzma_code, when checking reserved fields, skip fields past the
-   old end of the lzma_stream structure ifying reserved fields if and
-   only if this->internal->liblzma2_compat is false.
-
-That's it.  Hopefully this time it will work reliably.
-
-Thanks to Eduard Bloch for noticing PR13521 and to Ian Lance Taylor
-for PR12977.
-
-Patch-Name: liblzma-skip-ABI-incompatible-check-when-liblzma.so.patch
-Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
----
- configure.ac                |  5 +++++
- src/liblzma/common/common.c | 40 ++++++++++++++++++++++++++++++++++++++--
- src/liblzma/common/common.h |  4 ++++
- 3 files changed, 47 insertions(+), 2 deletions(-)
-
-diff --git a/configure.ac b/configure.ac
-index 53ae7bef7472..6dae0b9756d6 100644
---- a/configure.ac
-+++ b/configure.ac
-@@ -548,6 +548,11 @@ case $enable_threads in
- esac
- AM_CONDITIONAL([COND_THREADS], [test "x$enable_threads" != xno])
- 
-+# As a Debian-specific hack, liblzma uses dlopen() to check if extra
-+# paranoia is needed because unversioned symbols from liblzma.so.2 are
-+# present in the same process.  See src/liblzma/common/common.c.
-+AC_SEARCH_LIBS([dlopen], [dl])
-+
- echo
- echo "Initializing Libtool:"
- LT_PREREQ([2.2])
-diff --git a/src/liblzma/common/common.c b/src/liblzma/common/common.c
-index 28aa2b7142f4..5474211cf0ca 100644
---- a/src/liblzma/common/common.c
-+++ b/src/liblzma/common/common.c
-@@ -12,6 +12,8 @@
- 
- #include "common.h"
- 
-+#include <dlfcn.h>
-+
- 
- /////////////
- // Version //
-@@ -162,6 +164,17 @@ lzma_next_end(lzma_next_coder *next, const lzma_allocator *allocator)
- // External to internal API wrapper //
- //////////////////////////////////////
- 
-+static bool
-+liblzma2_loaded(void)
-+{
-+	void *handle = dlopen("liblzma.so.2", RTLD_LAZY | RTLD_NOLOAD);
-+	if (handle) {
-+		dlclose(handle);
-+		return true;
-+	}
-+	return false;
-+}
-+
- extern lzma_ret
- lzma_strm_init(lzma_stream *strm)
- {
-@@ -175,6 +188,7 @@ lzma_strm_init(lzma_stream *strm)
- 			return LZMA_MEM_ERROR;
- 
- 		strm->internal->next = LZMA_NEXT_CODER_INIT;
-+		strm->internal->liblzma2_compat = liblzma2_loaded();
- 	}
- 
- 	memzero(strm->internal->supported_actions,
-@@ -189,6 +203,24 @@ lzma_strm_init(lzma_stream *strm)
- }
- 
- 
-+// Before v5.0.0~6 (liblzma: A few ABI tweaks to reserve space in
-+// structures, 2010-10-23), the reserved fields in lzma_stream were:
-+//
-+//	void *reserved_ptr1;
-+//	void *reserved_ptr2;
-+//	uint64_t reserved_int1;
-+//	uint64_t reserved_int2;
-+//	lzma_reserved_enum reserved_enum1;
-+//	lzma_reserved_enum reserved_enum2;
-+//
-+// Nowadays there are two more pointers between reserved_ptr2 and
-+// reserved_int1 and two size_t fields between reserved_int2 and
-+// reserved_enum1.
-+//
-+// When strm->internal->liblzma2_compat is set, limit the checks of
-+// reserved fields to fields that were present in the old ABI to avoid
-+// segfaults and spurious "Unsupported options" from callers sharing
-+// the process image that expect the old ABI.
- extern LZMA_API(lzma_ret)
- lzma_code(lzma_stream *strm, lzma_action action)
- {
-@@ -206,8 +238,12 @@ lzma_code(lzma_stream *strm, lzma_action action)
- 	if (strm->reserved_ptr1 != NULL
- 			|| strm->reserved_ptr2 != NULL
- 			|| strm->reserved_ptr3 != NULL
--			|| strm->reserved_ptr4 != NULL
--			|| strm->reserved_int1 != 0
-+			|| strm->reserved_ptr4 != NULL)
-+		return LZMA_OPTIONS_ERROR;
-+
-+	if (strm->internal->liblzma2_compat)
-+		; /* Enough checks. */
-+	else if (strm->reserved_int1 != 0
- 			|| strm->reserved_int2 != 0
- 			|| strm->reserved_int3 != 0
- 			|| strm->reserved_int4 != 0
-diff --git a/src/liblzma/common/common.h b/src/liblzma/common/common.h
-index 955d784a5b6a..b056e417a29e 100644
---- a/src/liblzma/common/common.h
-+++ b/src/liblzma/common/common.h
-@@ -226,6 +226,10 @@ struct lzma_internal_s {
- 	/// If true, lzma_code will return LZMA_BUF_ERROR if no progress was
- 	/// made (no input consumed and no output produced by next.code).
- 	bool allow_buf_error;
-+
-+	/// Indicates whether we are sharing a process image with
-+	/// liblzma.so.2 and need to tread carefully.
-+	bool liblzma2_compat;
- };
- 
- 
diff --git a/debian/patches/series b/debian/patches/series
index 2236e2a..b5a37ef 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -1,3 +1 @@
-liblzma-skip-ABI-incompatible-check-when-liblzma.so.patch
-liblzma-make-dlopen-based-liblzma2-compatibility-opt.patch
 kfreebsd-link-against-libfreebsd-glue.patch
diff --git a/debian/xz-utils.README.Debian b/debian/xz-utils.README.Debian
index e1c7b97..7a06d2b 100644
--- a/debian/xz-utils.README.Debian
+++ b/debian/xz-utils.README.Debian
@@ -19,9 +19,7 @@
 ----------------------------------
 
 XZ Utils 5.1.y has some experimental features which are disabled in
-Debian to allow interfaces to evolve.  Debian liblzma is also modified
-to avoid breakage when the same process loads liblzma2 from Debian 6.0
-(squeeze) and liblzma5.
+Debian to allow interfaces to evolve.
 
 abi-threaded-encoder
   Disable threaded compression in liblzma and xz.
@@ -29,12 +27,6 @@
 abi-version-script
   liblzma: Do not pretend to satisfy dependencies on XZ_5.1.1alpha.
 
-abi-liblzma2-compat, configure-liblzma2-compat
-  Do not check reserved fields past the historical end of the
-  lzma_stream structure if liblzma.so.2 is loaded in the same
-  process image.  Likewise when linked statically.
-  (See bug #649522.)
-
 man-date, man-xz-lvv-minver (from upstream)
   Document the "Minimum version required to decompress" field of
   "xz --robot -v -v --list" output.
diff --git a/src/liblzma/common/common.c b/src/liblzma/common/common.c
index 79427b0..28aa2b7 100644
--- a/src/liblzma/common/common.c
+++ b/src/liblzma/common/common.c
@@ -12,8 +12,6 @@
 
 #include "common.h"
 
-#include <dlfcn.h>
-
 
 /////////////
 // Version //
@@ -164,47 +162,6 @@
 // External to internal API wrapper //
 //////////////////////////////////////
 
-#ifdef LIBLZMA2_COMPAT_DYNAMIC
-
-static void
-init_liblzma2_compat(lzma_stream *strm)
-{
-	void *handle = dlopen("liblzma.so.2", RTLD_LAZY | RTLD_NOLOAD);
-	if (handle) {
-		dlclose(handle);
-		strm->internal->liblzma2_compat = true;
-		return;
-	}
-	strm->internal->liblzma2_compat = false;
-}
-
-static bool
-liblzma2_loaded(lzma_stream *strm)
-{
-	return strm->internal->liblzma2_compat;
-}
-
-#else
-
-static void
-init_liblzma2_compat(lzma_stream *strm)
-{
-}
-
-#ifdef LIBLZMA2_COMPAT
-static bool liblzma2_loaded(lzma_stream *strm)
-{
-	return true;
-}
-#else
-static bool liblzma2_loaded(lzma_stream *strm)
-{
-	return false;
-}
-#endif
-
-#endif
-
 extern lzma_ret
 lzma_strm_init(lzma_stream *strm)
 {
@@ -218,7 +175,6 @@
 			return LZMA_MEM_ERROR;
 
 		strm->internal->next = LZMA_NEXT_CODER_INIT;
-		init_liblzma2_compat(strm);
 	}
 
 	memzero(strm->internal->supported_actions,
@@ -233,24 +189,6 @@
 }
 
 
-// Before v5.0.0~6 (liblzma: A few ABI tweaks to reserve space in
-// structures, 2010-10-23), the reserved fields in lzma_stream were:
-//
-//	void *reserved_ptr1;
-//	void *reserved_ptr2;
-//	uint64_t reserved_int1;
-//	uint64_t reserved_int2;
-//	lzma_reserved_enum reserved_enum1;
-//	lzma_reserved_enum reserved_enum2;
-//
-// Nowadays there are two more pointers between reserved_ptr2 and
-// reserved_int1 and two size_t fields between reserved_int2 and
-// reserved_enum1.
-//
-// When strm->internal->liblzma2_compat is set, limit the checks of
-// reserved fields to fields that were present in the old ABI to avoid
-// segfaults and spurious "Unsupported options" from callers sharing
-// the process image that expect the old ABI.
 extern LZMA_API(lzma_ret)
 lzma_code(lzma_stream *strm, lzma_action action)
 {
@@ -268,12 +206,8 @@
 	if (strm->reserved_ptr1 != NULL
 			|| strm->reserved_ptr2 != NULL
 			|| strm->reserved_ptr3 != NULL
-			|| strm->reserved_ptr4 != NULL)
-		return LZMA_OPTIONS_ERROR;
-
-	if (liblzma2_loaded(strm))
-		; /* Enough checks. */
-	else if (strm->reserved_int1 != 0
+			|| strm->reserved_ptr4 != NULL
+			|| strm->reserved_int1 != 0
 			|| strm->reserved_int2 != 0
 			|| strm->reserved_int3 != 0
 			|| strm->reserved_int4 != 0
diff --git a/src/liblzma/common/common.h b/src/liblzma/common/common.h
index eb1d052..955d784 100644
--- a/src/liblzma/common/common.h
+++ b/src/liblzma/common/common.h
@@ -226,12 +226,6 @@
 	/// If true, lzma_code will return LZMA_BUF_ERROR if no progress was
 	/// made (no input consumed and no output produced by next.code).
 	bool allow_buf_error;
-
-#ifdef LIBLZMA2_COMPAT_DYNAMIC
-	/// Indicates whether we are sharing a process image with
-	/// liblzma.so.2 and need to tread carefully.
-	bool liblzma2_compat;
-#endif
 };