diff --git a/build/VS2008/zstd/zstd.vcproj b/build/VS2008/zstd/zstd.vcproj
index de1501d20..fc87625a9 100644
--- a/build/VS2008/zstd/zstd.vcproj
+++ b/build/VS2008/zstd/zstd.vcproj
@@ -45,7 +45,7 @@
 				Name="VCCLCompilerTool"
 				Optimization="0"
 				AdditionalIncludeDirectories="$(SolutionDir)..\..\lib;$(SolutionDir)..\..\lib\common;$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\lib\dictBuilder;$(SolutionDir)..\..\lib\compress"
-				PreprocessorDefinitions="ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;_DEBUG;_CONSOLE"
+				PreprocessorDefinitions="ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;_DEBUG;_CONSOLE"
 				MinimalRebuild="true"
 				BasicRuntimeChecks="3"
 				RuntimeLibrary="3"
@@ -122,7 +122,7 @@
 				EnableIntrinsicFunctions="true"
 				OmitFramePointers="true"
 				AdditionalIncludeDirectories="$(SolutionDir)..\..\lib;$(SolutionDir)..\..\lib\common;$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\lib\dictBuilder;$(SolutionDir)..\..\lib\compress"
-				PreprocessorDefinitions="ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;NDEBUG;_CONSOLE"
+				PreprocessorDefinitions="ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;NDEBUG;_CONSOLE"
 				RuntimeLibrary="0"
 				EnableFunctionLevelLinking="true"
 				UsePrecompiledHeader="0"
@@ -197,7 +197,7 @@
 				Name="VCCLCompilerTool"
 				Optimization="0"
 				AdditionalIncludeDirectories="$(SolutionDir)..\..\lib;$(SolutionDir)..\..\lib\common;$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\lib\dictBuilder;$(SolutionDir)..\..\lib\compress"
-				PreprocessorDefinitions="ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;_DEBUG;_CONSOLE"
+				PreprocessorDefinitions="ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;_DEBUG;_CONSOLE"
 				MinimalRebuild="true"
 				BasicRuntimeChecks="3"
 				RuntimeLibrary="3"
@@ -275,7 +275,7 @@
 				EnableIntrinsicFunctions="true"
 				OmitFramePointers="true"
 				AdditionalIncludeDirectories="$(SolutionDir)..\..\lib;$(SolutionDir)..\..\lib\common;$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\lib\dictBuilder;$(SolutionDir)..\..\lib\compress"
-				PreprocessorDefinitions="ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;NDEBUG;_CONSOLE"
+				PreprocessorDefinitions="ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;NDEBUG;_CONSOLE"
 				RuntimeLibrary="0"
 				EnableFunctionLevelLinking="true"
 				UsePrecompiledHeader="0"
diff --git a/build/VS2008/zstdlib/zstdlib.vcproj b/build/VS2008/zstdlib/zstdlib.vcproj
index 88c1aee26..61c88f5bc 100644
--- a/build/VS2008/zstdlib/zstdlib.vcproj
+++ b/build/VS2008/zstdlib/zstdlib.vcproj
@@ -45,7 +45,7 @@
 				Name="VCCLCompilerTool"
 				Optimization="0"
 				AdditionalIncludeDirectories="$(SolutionDir)..\..\lib;$(SolutionDir)..\..\lib\common;$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\programs\legacy;$(SolutionDir)..\..\lib\dictBuilder"
-				PreprocessorDefinitions="ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;_DEBUG;_CONSOLE"
+				PreprocessorDefinitions="ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;_DEBUG;_CONSOLE"
 				MinimalRebuild="true"
 				BasicRuntimeChecks="3"
 				RuntimeLibrary="3"
@@ -121,7 +121,7 @@
 				EnableIntrinsicFunctions="true"
 				OmitFramePointers="true"
 				AdditionalIncludeDirectories="$(SolutionDir)..\..\lib;$(SolutionDir)..\..\lib\common;$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\programs\legacy;$(SolutionDir)..\..\lib\dictBuilder"
-				PreprocessorDefinitions="ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;NDEBUG;_CONSOLE"
+				PreprocessorDefinitions="ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;NDEBUG;_CONSOLE"
 				RuntimeLibrary="0"
 				EnableFunctionLevelLinking="true"
 				UsePrecompiledHeader="0"
@@ -195,7 +195,7 @@
 				Name="VCCLCompilerTool"
 				Optimization="0"
 				AdditionalIncludeDirectories="$(SolutionDir)..\..\lib;$(SolutionDir)..\..\lib\common;$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\programs\legacy;$(SolutionDir)..\..\lib\dictBuilder"
-				PreprocessorDefinitions="ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;_DEBUG;_CONSOLE"
+				PreprocessorDefinitions="ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;_DEBUG;_CONSOLE"
 				MinimalRebuild="true"
 				BasicRuntimeChecks="3"
 				RuntimeLibrary="3"
@@ -272,7 +272,7 @@
 				EnableIntrinsicFunctions="true"
 				OmitFramePointers="true"
 				AdditionalIncludeDirectories="$(SolutionDir)..\..\lib;$(SolutionDir)..\..\lib\common;$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\programs\legacy;$(SolutionDir)..\..\lib\dictBuilder"
-				PreprocessorDefinitions="ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;NDEBUG;_CONSOLE"
+				PreprocessorDefinitions="ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;NDEBUG;_CONSOLE"
 				RuntimeLibrary="0"
 				EnableFunctionLevelLinking="true"
 				UsePrecompiledHeader="0"
diff --git a/build/VS2010/libzstd-dll/libzstd-dll.vcxproj b/build/VS2010/libzstd-dll/libzstd-dll.vcxproj
index 6925e0f9e..ddb8e3216 100644
--- a/build/VS2010/libzstd-dll/libzstd-dll.vcxproj
+++ b/build/VS2010/libzstd-dll/libzstd-dll.vcxproj
@@ -169,7 +169,7 @@
       </PrecompiledHeader>
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
-      <PreprocessorDefinitions>ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;_DEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;_DEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
       <DebugInformationFormat>EditAndContinue</DebugInformationFormat>
@@ -188,7 +188,7 @@
       </PrecompiledHeader>
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
-      <PreprocessorDefinitions>ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;_DEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;_DEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <TreatWarningAsError>true</TreatWarningAsError>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
@@ -208,7 +208,7 @@
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
-      <PreprocessorDefinitions>ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;NDEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;NDEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <EnablePREfast>false</EnablePREfast>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
@@ -229,7 +229,7 @@
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
-      <PreprocessorDefinitions>ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;NDEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_DLL_EXPORT=1;ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;NDEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <TreatWarningAsError>false</TreatWarningAsError>
       <EnablePREfast>false</EnablePREfast>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
diff --git a/build/VS2010/libzstd/libzstd.vcxproj b/build/VS2010/libzstd/libzstd.vcxproj
index 82a2d8268..09ead245a 100644
--- a/build/VS2010/libzstd/libzstd.vcxproj
+++ b/build/VS2010/libzstd/libzstd.vcxproj
@@ -162,7 +162,7 @@
       </PrecompiledHeader>
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
-      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;_DEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;_DEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
       <DebugInformationFormat>EditAndContinue</DebugInformationFormat>
@@ -181,7 +181,7 @@
       </PrecompiledHeader>
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
-      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;_DEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;_DEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <TreatWarningAsError>true</TreatWarningAsError>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
@@ -201,7 +201,7 @@
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
-      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;NDEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;NDEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <EnablePREfast>false</EnablePREfast>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
@@ -222,7 +222,7 @@
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
-      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;NDEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;NDEBUG;_CONSOLE;_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <TreatWarningAsError>false</TreatWarningAsError>
       <EnablePREfast>false</EnablePREfast>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
diff --git a/build/VS2010/zstd/zstd.vcxproj b/build/VS2010/zstd/zstd.vcxproj
index 0558687f5..230fd7d09 100644
--- a/build/VS2010/zstd/zstd.vcxproj
+++ b/build/VS2010/zstd/zstd.vcxproj
@@ -187,7 +187,7 @@
       </PrecompiledHeader>
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
-      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <TreatWarningAsError>true</TreatWarningAsError>
       <EnablePREfast>false</EnablePREfast>
       <EnableEnhancedInstructionSet>$(InstructionSet)</EnableEnhancedInstructionSet>
@@ -204,7 +204,7 @@
       </PrecompiledHeader>
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
-      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <TreatWarningAsError>true</TreatWarningAsError>
       <EnablePREfast>false</EnablePREfast>
       <EnableEnhancedInstructionSet>$(InstructionSet)</EnableEnhancedInstructionSet>
@@ -223,7 +223,7 @@
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
-      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <EnablePREfast>false</EnablePREfast>
       <TreatWarningAsError>false</TreatWarningAsError>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
@@ -245,7 +245,7 @@
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
-      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=5;WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>ZSTD_MULTITHREAD=1;ZSTD_LEGACY_SUPPORT=0;WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <TreatWarningAsError>false</TreatWarningAsError>
       <EnablePREfast>false</EnablePREfast>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
diff --git a/build/meson/meson_options.txt b/build/meson/meson_options.txt
index 470517827..8d7b8856e 100644
--- a/build/meson/meson_options.txt
+++ b/build/meson/meson_options.txt
@@ -10,8 +10,8 @@
 
 # Read guidelines from https://wiki.gnome.org/Initiatives/GnomeGoals/MesonPorting
 
-option('legacy_level', type: 'integer', min: 0, max: 7, value: 5,
-  description: 'Support any legacy format: 7 to 1 for v0.7+ to v0.1+')
+option('legacy_level', type: 'integer', min: 0, max: 7, value: 0,
+  description: 'Support legacy format: 0=disabled, 1-7=support v0.1+ to v0.7+')
 option('debug_level', type: 'integer', min: 0, max: 9, value: 1,
   description: 'Enable run-time debug. See lib/common/debug.h')
 option('backtrace', type: 'feature', value: 'disabled',
diff --git a/lib/BUCK b/lib/BUCK
index 60c6bbb54..8c555a8be 100644
--- a/lib/BUCK
+++ b/lib/BUCK
@@ -57,7 +57,7 @@ cxx_library(
     srcs=glob(['legacy/*.c']),
     deps=[':common'],
     exported_preprocessor_flags=[
-        '-DZSTD_LEGACY_SUPPORT=4',
+        '-DZSTD_LEGACY_SUPPORT=0',
     ],
 )
 
diff --git a/tests/Makefile b/tests/Makefile
index 643f8cd61..c74c219dc 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -20,7 +20,7 @@
 # zstreamtest32: Same as zstreamtest, but forced to compile in 32-bits mode
 # ##########################################################################
 
-ZSTD_LEGACY_SUPPORT ?= 5
+ZSTD_LEGACY_SUPPORT ?= 0
 export ZSTD_LEGACY_SUPPORT
 
 DEBUGLEVEL ?= 2