diff --git a/changelog/toolchain_requirements.dd b/changelog/toolchain_requirements.dd
index b72fb79..d27f8bb 100644
--- a/changelog/toolchain_requirements.dd
+++ b/changelog/toolchain_requirements.dd
@@ -8,7 +8,7 @@
 {
     "toolchainRequirements": {
         "dub": "~>1.10",
-        "frontend": ">=2.068|<2.083"
+        "frontend": ">=2.068 <2.083"
     }
 }
 ---
@@ -27,9 +27,11 @@
     $(LI gdc)
 )
 
-Each can be assigned to one or more version specifications, separated by `|`.
-For compilers, instead of a version specification, the keyword `no` can also be
-used to indicate that the compiler should not be used for this package.
+Each can contain a
+$(LINK2 https://dub.pm/package-format-sdl.html#version-specs, version specification),
+where DMD-like versions are supported in addition to SemVer versions. For
+compilers, instead of a version specification, the keyword `no` can also be used
+to indicate that the compiler should not be used for this package.
 
 Example scenario:$(BR)
 Package that needs DUB>=1.12, and that will only build with LDC>=1.10:
diff --git a/source/dub/compilers/compiler.d b/source/dub/compilers/compiler.d
index b087cd8..b6a96cc 100644
--- a/source/dub/compilers/compiler.d
+++ b/source/dub/compilers/compiler.d
@@ -8,6 +8,7 @@
 module dub.compilers.compiler;
 
 public import dub.compilers.buildsettings;
+public import dub.dependency : Dependency;
 public import dub.platform : BuildPlatform, matchesSpecification;
 
 import dub.internal.vibecompat.core.file;
@@ -91,46 +92,6 @@
 	/// Convert linker flags to compiler format
 	string[] lflagsToDFlags(in string[] lflags) const;
 
-	/// Get the dependency requirement string for this compiler
-	string toolchainRequirementString(const ref ToolchainRequirements tr);
-
-	/// Check whether the compiler meet the compiler requirement specified
-	/// in the recipe.
-	bool checkCompilerRequirement(const ref BuildPlatform platform, const ref ToolchainRequirements tr);
-
-	/// Check if the compiler is supported by the recipe
-	final bool checkCompilerSupported(const ref ToolchainRequirements tr)
-	{
-		const str = toolchainRequirementString(tr);
-		return str != ToolchainRequirements.noKwd;
-	}
-
-	/// Check whether the compiler meet the frontend requirement specified
-	/// in the recipe.
-	final bool checkFrontendRequirement(const ref BuildPlatform platform, const ref ToolchainRequirements tr)
-	{
-		import std.typecons : Yes;
-
-		return checkRequirement(tr.frontend, platform.frontendVersionString, Yes.dmdVer);
-	}
-
-	/// Check that a particular tool version matches with a given requirement
-	final bool checkRequirement(const string requirement, const string toolVer, const Flag!"dmdVer" dmdVer)
-	{
-		import dub.compilers.utils : dmdLikeVersionToSemverLike;
-		import dub.dependency : Dependency, Version;
-		import std.algorithm : all, map, splitter;
-
-		if (!requirement.length) return true; // no requirement
-
-		const ver = Version(dmdVer ? dmdLikeVersionToSemverLike(toolVer) : toolVer);
-
-		return requirement
-			.splitter('|')
-			.map!(r => Dependency(dmdVer ? dmdLikeVersionToSemverLike(r) : r))
-			.all!(r => r.matches(ver));
-	}
-
 	/** Runs a tool and provides common boilerplate code.
 
 		This method should be used by `Compiler` implementations to invoke the
diff --git a/source/dub/compilers/dmd.d b/source/dub/compilers/dmd.d
index d362413..ac0a459 100644
--- a/source/dub/compilers/dmd.d
+++ b/source/dub/compilers/dmd.d
@@ -265,18 +265,6 @@
 		return  lflags.map!(f => "-L"~f)().array();
 	}
 
-	string toolchainRequirementString(const ref ToolchainRequirements tr)
-	{
-		return tr.dmd;
-	}
-
-	bool checkCompilerRequirement(const ref BuildPlatform platform, const ref ToolchainRequirements tr)
-	{
-		import std.typecons : Yes;
-
-		return checkRequirement(tr.dmd, platform.compilerVersion, Yes.dmdVer);
-	}
-
 	private auto escapeArgs(in string[] args)
 	{
 		return args.map!(s => s.canFind(' ') ? "\""~s~"\"" : s);
diff --git a/source/dub/compilers/gdc.d b/source/dub/compilers/gdc.d
index dc4d118..53225e3 100644
--- a/source/dub/compilers/gdc.d
+++ b/source/dub/compilers/gdc.d
@@ -256,18 +256,6 @@
 
 		return  dflags;
 	}
-
-	final string toolchainRequirementString(const ref ToolchainRequirements tr)
-	{
-		return tr.gdc;
-	}
-
-	final bool checkCompilerRequirement(const ref BuildPlatform platform, const ref ToolchainRequirements tr)
-	{
-		import std.typecons : No;
-
-		return checkRequirement(tr.gdc, platform.compilerVersion, No.dmdVer);
-	}
 }
 
 private string extractTarget(const string[] args) { auto i = args.countUntil("-o"); return i >= 0 ? args[i+1] : null; }
diff --git a/source/dub/compilers/ldc.d b/source/dub/compilers/ldc.d
index ae3ed22..4522825 100644
--- a/source/dub/compilers/ldc.d
+++ b/source/dub/compilers/ldc.d
@@ -233,18 +233,6 @@
 		return  lflags.map!(s => "-L="~s)().array();
 	}
 
-	final string toolchainRequirementString(const ref ToolchainRequirements tr)
-	{
-		return tr.ldc;
-	}
-
-	final bool checkCompilerRequirement(const ref BuildPlatform platform, const ref ToolchainRequirements tr)
-	{
-		import std.typecons : No;
-
-		return checkRequirement(tr.ldc, platform.compilerVersion, No.dmdVer);
-	}
-
 	private auto escapeArgs(in string[] args)
 	{
 		return args.map!(s => s.canFind(' ') ? "\""~s~"\"" : s);
diff --git a/source/dub/compilers/utils.d b/source/dub/compilers/utils.d
index fc60a35..03b3c33 100644
--- a/source/dub/compilers/utils.d
+++ b/source/dub/compilers/utils.d
@@ -247,7 +247,7 @@
 	Returns:
 		A Semver compliant string
 */
-string dmdLikeVersionToSemverLike(string ver)
+package(dub) string dmdLikeVersionToSemverLike(string ver)
 {
 	import std.algorithm : countUntil, joiner, map, skipOver, splitter;
 	import std.array : join, split;
diff --git a/source/dub/dependency.d b/source/dub/dependency.d
index cd6c01d..da1b552 100644
--- a/source/dub/dependency.d
+++ b/source/dub/dependency.d
@@ -138,6 +138,8 @@
 	*/
 	@property void versionSpec(string ves)
 	{
+		static import std.string;
+
 		enforce(ves.length > 0);
 		string orig = ves;
 
@@ -200,6 +202,8 @@
 	/// ditto
 	@property string versionSpec()
 	const {
+		static import std.string;
+
 		string r;
 
 		if (this == invalid) return "invalid";
diff --git a/source/dub/generators/build.d b/source/dub/generators/build.d
index c88535d..b3b239c 100644
--- a/source/dub/generators/build.d
+++ b/source/dub/generators/build.d
@@ -50,47 +50,13 @@
 
 		void checkPkgRequirements(const(Package) pkg)
 		{
-			import std.format : format;
-
 			const tr = pkg.recipe.toolchainRequirements;
-
-			enforce (
-				dcl.checkCompilerSupported(tr),
-				format(
-					"Installed %s-%s is not supported by %s. Supported compiler(s):\n%s",
-					dcl.name, settings.platform.compilerVersion, pkg.name,
-					tr.supportedCompilers.map!((string[2] cs) {
-						auto str = "  - " ~ cs[0];
-						if (cs[1].length) str ~= ": "~cs[1];
-						return str;
-					}).join("\n")
-				)
-			);
-
-			enforce(
-				dcl.checkCompilerRequirement(settings.platform, tr),
-				format(
-					"Installed %s-%s does not comply with %s compiler requirement: %s %s\n" ~
-					"Please consider upgrading your installation.",
-					dcl.name, settings.platform.compilerVersion,
-					pkg.name, dcl.name, dcl.toolchainRequirementString( tr )
-				)
-			);
-			enforce(
-				dcl.checkFrontendRequirement(settings.platform, tr),
-				format(
-					"Installed %s-%s with frontend %s does not comply with %s frontend requirement: %s\n" ~
-					"Please consider upgrading your installation.",
-					dcl.name, settings.platform.compilerVersion,
-					settings.platform.frontendVersionString, pkg.name, tr.frontend
-				)
-			);
+			tr.checkPlatform(settings.platform, pkg.name);
 		}
 
 		checkPkgRequirements(m_project.rootPackage);
-		foreach (pkg; m_project.dependencies) {
+		foreach (pkg; m_project.dependencies)
 			checkPkgRequirements(pkg);
-		}
 
 		auto root_ti = targets[m_project.rootPackage.name];
 
diff --git a/source/dub/package_.d b/source/dub/package_.d
index 1c1858e..88e3765 100644
--- a/source/dub/package_.d
+++ b/source/dub/package_.d
@@ -551,15 +551,13 @@
 	// Left as package until the final API for this has been found
 	package auto getAllDependenciesRange()
 	const {
-		return this.recipe.buildSettings.dependencies.byKeyValue
-			.map!(bs => PackageDependency(bs.key, bs.value))
-			.chain(
-				this.recipe.configurations
-					.map!(c => c.buildSettings.dependencies.byKeyValue
-						.map!(bs => PackageDependency(bs.key, bs.value))
-					)
-					.joiner()
-			);
+		return
+			chain(
+				only(this.recipe.buildSettings.dependencies.byKeyValue),
+				this.recipe.configurations.map!(c => c.buildSettings.dependencies.byKeyValue)
+			)
+			.joiner()
+			.map!(d => PackageDependency(d.key, d.value));
 	}
 
 
@@ -643,23 +641,21 @@
 		import dub.version_ : dubVersion;
 		import std.exception : enforce;
 
-		if (m_info.toolchainRequirements.dub.length) {
-			const dep = Dependency(m_info.toolchainRequirements.dub);
+		const dep = m_info.toolchainRequirements.dub;
 
-			static assert(dubVersion.length);
-			static if (dubVersion[0] == 'v') {
-				enum dv = dubVersion[1 .. $];
-			}
-			else {
-				enum dv = dubVersion;
-			}
-			static assert(isValidVersion(dv));
-
-			enforce(dep.matches(dv),
-				"dub-"~dv~" does not comply with toolchainRequirements.dub " ~
-				"specification: "~m_info.toolchainRequirements.dub~
-				"\nPlease consider upgrading your DUB installation");
+		static assert(dubVersion.length);
+		static if (dubVersion[0] == 'v') {
+			enum dv = dubVersion[1 .. $];
 		}
+		else {
+			enum dv = dubVersion;
+		}
+		static assert(isValidVersion(dv));
+
+		enforce(dep.matches(dv),
+			"dub-" ~ dv ~ " does not comply with toolchainRequirements.dub "
+			~ "specification: " ~ m_info.toolchainRequirements.dub.toString()
+			~ "\nPlease consider upgrading your DUB installation");
 	}
 
 	private void fillWithDefaults()
diff --git a/source/dub/recipe/json.d b/source/dub/recipe/json.d
index c1fd9a1..354a1e6 100644
--- a/source/dub/recipe/json.d
+++ b/source/dub/recipe/json.d
@@ -106,7 +106,7 @@
 			types[name] = settings.toJson();
 		ret["buildTypes"] = types;
 	}
-	if (recipe.hasToolchainRequirements) {
+	if (!recipe.toolchainRequirements.empty) {
 		ret["toolchainRequirements"] = recipe.toolchainRequirements.toJson();
 	}
 	if (!recipe.ddoxFilterArgs.empty) ret["-ddoxFilterArgs"] = recipe.ddoxFilterArgs.serializeToJson();
@@ -300,46 +300,17 @@
 
 private void parseJson(ref ToolchainRequirements tr, Json json)
 {
-	foreach (string name, value; json) {
-		switch (name) {
-		case "dub":
-			tr.dub = value.get!string();
-			break;
-		case "frontend":
-			tr.frontend = value.get!string();
-			break;
-		case "dmd":
-			tr.dmd = value.get!string();
-			break;
-		case "ldc":
-			tr.ldc = value.get!string();
-			break;
-		case "gdc":
-			tr.gdc = value.get!string();
-			break;
-		default:
-			break;
-		}
-	}
+	foreach (string name, value; json)
+		tr.addRequirement(name, value.get!string);
 }
 
 private Json toJson(in ref ToolchainRequirements tr)
 {
 	auto ret = Json.emptyObject;
-	if (tr.dub.length) {
-		ret["dub"] = serializeToJson(tr.dub);
-	}
-	if (tr.frontend.length) {
-		ret["frontend"] = serializeToJson(tr.frontend);
-	}
-	if (tr.dmd.length) {
-		ret["dmd"] = serializeToJson(tr.dmd);
-	}
-	if (tr.ldc.length) {
-		ret["ldc"] = serializeToJson(tr.ldc);
-	}
-	if (tr.gdc.length) {
-		ret["gdc"] = serializeToJson(tr.gdc);
-	}
+	if (tr.dub != Dependency.any) ret["dub"] = serializeToJson(tr.dub);
+	if (tr.frontend != Dependency.any) ret["frontend"] = serializeToJson(tr.frontend);
+	if (tr.dmd != Dependency.any) ret["dmd"] = serializeToJson(tr.dmd);
+	if (tr.ldc != Dependency.any) ret["ldc"] = serializeToJson(tr.ldc);
+	if (tr.gdc != Dependency.any) ret["gdc"] = serializeToJson(tr.gdc);
 	return ret;
 }
diff --git a/source/dub/recipe/packagerecipe.d b/source/dub/recipe/packagerecipe.d
index f1d3c3e..5a73030 100644
--- a/source/dub/recipe/packagerecipe.d
+++ b/source/dub/recipe/packagerecipe.d
@@ -98,17 +98,6 @@
 		throw new Exception("Unknown configuration: "~name);
 	}
 
-	bool hasToolchainRequirements() const
-	{
-		import std.algorithm : any;
-		import std.range : only;
-
-		with (toolchainRequirements) {
-			return only(dub, frontend, dmd, ldc, gdc)
-				.any!(r => r.length != 0);
-		}
-	}
-
 	/** Clones the package recipe recursively.
 	*/
 	PackageRecipe clone() const { return .clone(this); }
@@ -123,28 +112,39 @@
 /// Describes minimal toolchain requirements
 struct ToolchainRequirements
 {
-	/// DUB version requirement
-	string dub;
-	/// D front-end version requirement
-	string frontend;
-	/// DMD version requirement
-	string dmd;
-	/// LDC version requirement
-	string ldc;
-	/// GDC version requirement
-	string gdc;
+	import std.typecons : Tuple, tuple;
 
-	package(dub) enum noKwd = "no";
-	/// Get the list of supported compilers.
-	/// Returns: array of couples of compiler name and compiler requirement
-	@property string[2][] supportedCompilers() const
+	/// DUB version requirement
+	Dependency dub = Dependency.any;
+	/// D front-end version requirement
+	Dependency frontend = Dependency.any;
+	/// DMD version requirement
+	Dependency dmd = Dependency.any;
+	/// LDC version requirement
+	Dependency ldc = Dependency.any;
+	/// GDC version requirement
+	Dependency gdc = Dependency.any;
+
+	/** Get the list of supported compilers.
+
+		Returns:
+			An array of couples of compiler name and compiler requirement
+	*/
+	@property Tuple!(string, Dependency)[] supportedCompilers() const
 	{
-		string[2][] res;
-		if (dmd != noKwd) res ~= [ "dmd", dmd ];
-		if (ldc != noKwd) res ~= [ "ldc", ldc ];
-		if (gdc != noKwd) res ~= [ "gdc", gdc ];
+		Tuple!(string, Dependency)[] res;
+		if (dmd != Dependency.invalid) res ~= Tuple!(string, Dependency)("dmd", dmd);
+		if (ldc != Dependency.invalid) res ~= Tuple!(string, Dependency)("ldc", ldc);
+		if (gdc != Dependency.invalid) res ~= Tuple!(string, Dependency)("gdc", gdc);
 		return res;
 	}
+
+	bool empty()
+	const {
+		import std.algorithm.searching : all;
+		return only(dub, frontend, dmd, ldc, gdc)
+			.all!(r => r == Dependency.any);
+	}
 }
 
 
@@ -330,6 +330,103 @@
 	}
 }
 
+package(dub) void checkPlatform(in ref ToolchainRequirements tr, BuildPlatform platform, string package_name)
+{
+	import dub.compilers.utils : dmdLikeVersionToSemverLike;
+	import std.algorithm.iteration : map;
+	import std.format : format;
+
+	string compilerver;
+	Dependency compilerspec;
+
+	switch (platform.compiler) {
+		default:
+			compilerspec = Dependency.any;
+			compilerver = "0.0.0";
+			break;
+		case "dmd":
+			compilerspec = tr.dmd;
+			compilerver = platform.compilerVersion.length
+				? dmdLikeVersionToSemverLike(platform.compilerVersion)
+				: "0.0.0";
+			break;
+		case "ldc":
+			compilerspec = tr.ldc;
+			compilerver = platform.compilerVersion;
+			if (!compilerver.length) compilerver = "0.0.0";
+			break;
+		case "gdc":
+			compilerspec = tr.gdc;
+			compilerver = platform.compilerVersion;
+			if (!compilerver.length) compilerver = "0.0.0";
+			break;
+	}
+
+	enforce(compilerspec != Dependency.invalid,
+		format(
+			"Installed %s %s is not supported by %s. Supported compiler(s):\n%s",
+			platform.compiler, platform.compilerVersion, package_name,
+			tr.supportedCompilers.map!((cs) {
+				auto str = "  - " ~ cs[0];
+				if (cs[1] != Dependency.any) str ~= ": " ~ cs[1].toString();
+				return str;
+			}).join("\n")
+		)
+	);
+
+	enforce(compilerspec.matches(compilerver),
+		format(
+			"Installed %s-%s does not comply with %s compiler requirement: %s %s\n" ~
+			"Please consider upgrading your installation.",
+			platform.compiler, platform.compilerVersion,
+			package_name, platform.compiler, compilerspec
+		)
+	);
+
+	enforce(tr.frontend.matches(dmdLikeVersionToSemverLike(platform.frontendVersionString)),
+		format(
+			"Installed %s-%s with frontend %s does not comply with %s frontend requirement: %s\n" ~
+			"Please consider upgrading your installation.",
+			platform.compiler, platform.compilerVersion,
+			platform.frontendVersionString, package_name, tr.frontend
+		)
+	);
+}
+
+package bool addRequirement(ref ToolchainRequirements req, string name, string value)
+{
+	switch (name) {
+		default: return false;
+		case "dub": req.dub = parseDependency(value); break;
+		case "frontend": req.frontend = parseDMDDependency(value); break;
+		case "ldc": req.ldc = parseDependency(value); break;
+		case "gdc": req.gdc = parseDependency(value); break;
+		case "dmd": req.dmd = parseDMDDependency(value); break;
+	}
+	return true;
+}
+
+private static Dependency parseDependency(string dep)
+{
+	if (dep == "no") return Dependency.invalid;
+	return Dependency(dep);
+}
+
+private static Dependency parseDMDDependency(string dep)
+{
+	import dub.compilers.utils : dmdLikeVersionToSemverLike;
+	import dub.dependency : Dependency;
+	import std.algorithm : map, splitter;
+	import std.array : join;
+
+	if (dep == "no") return Dependency.invalid;
+	return dep
+		.splitter(' ')
+		.map!(r => dmdLikeVersionToSemverLike(r))
+		.join(' ')
+		.Dependency;
+}
+
 private T clone(T)(ref const(T) val)
 {
 	import std.traits : isSomeString, isDynamicArray, isAssociativeArray, isBasicType, ValueType;
diff --git a/source/dub/recipe/sdl.d b/source/dub/recipe/sdl.d
index d3aaf14..09e8b8d 100644
--- a/source/dub/recipe/sdl.d
+++ b/source/dub/recipe/sdl.d
@@ -104,7 +104,7 @@
 		t.add(settings.toSDL());
 		ret.add(t);
 	}
-	if (recipe.hasToolchainRequirements) {
+	if (!recipe.toolchainRequirements.empty) {
 		ret.add(toSDL(recipe.toolchainRequirements));
 	}
 	if (recipe.ddoxFilterArgs.length)
@@ -280,47 +280,18 @@
 
 private void parseToolchainRequirements(ref ToolchainRequirements tr, Tag tag)
 {
-	foreach (attr; tag.attributes) {
-		switch (attr.name) {
-		case "dub":
-			tr.dub = attr.value.get!string();
-			break;
-		case "frontend":
-			tr.frontend = attr.value.get!string();
-			break;
-		case "dmd":
-			tr.dmd = attr.value.get!string();
-			break;
-		case "ldc":
-			tr.ldc = attr.value.get!string();
-			break;
-		case "gdc":
-			tr.gdc = attr.value.get!string();
-			break;
-		default:
-			break;
-		}
-	}
+	foreach (attr; tag.attributes)
+		tr.addRequirement(attr.name, attr.value.get!string);
 }
 
 private Tag toSDL(const ref ToolchainRequirements tr)
 {
 	Attribute[] attrs;
-	if (tr.dub.length) {
-		attrs ~= new Attribute("dub", Value(tr.dub));
-	}
-	if (tr.frontend.length) {
-		attrs ~= new Attribute("frontend", Value(tr.frontend));
-	}
-	if (tr.dmd.length) {
-		attrs ~= new Attribute("dmd", Value(tr.dmd));
-	}
-	if (tr.ldc.length) {
-		attrs ~= new Attribute("ldc", Value(tr.ldc));
-	}
-	if (tr.gdc.length) {
-		attrs ~= new Attribute("gdc", Value(tr.gdc));
-	}
+	if (tr.dub != Dependency.any) attrs ~= new Attribute("dub", Value(tr.dub.toString()));
+	if (tr.frontend != Dependency.any) attrs ~= new Attribute("frontend", Value(tr.frontend.toString()));
+	if (tr.dmd != Dependency.any) attrs ~= new Attribute("dmd", Value(tr.dmd.toString()));
+	if (tr.ldc != Dependency.any) attrs ~= new Attribute("ldc", Value(tr.ldc.toString()));
+	if (tr.gdc != Dependency.any) attrs ~= new Attribute("gdc", Value(tr.gdc.toString()));
 	return new Tag(null, "toolchainRequirements", null, attrs);
 }
 
@@ -510,11 +481,11 @@
 	assert(rec.buildTypes.length == 2);
 	assert(rec.buildTypes["debug"].dflags == ["": ["-g", "-debug"]]);
 	assert(rec.buildTypes["release"].dflags == ["": ["-release", "-O"]]);
-	assert(rec.toolchainRequirements.dub == "~>1.11.0");
-	assert(rec.toolchainRequirements.frontend is null);
-	assert(rec.toolchainRequirements.dmd == "~>2.082");
-	assert(rec.toolchainRequirements.ldc is null);
-	assert(rec.toolchainRequirements.gdc is null);
+	assert(rec.toolchainRequirements.dub == Dependency("~>1.11.0"));
+	assert(rec.toolchainRequirements.frontend == Dependency.any);
+	assert(rec.toolchainRequirements.dmd == Dependency("~>2.82.0"));
+	assert(rec.toolchainRequirements.ldc == Dependency.any);
+	assert(rec.toolchainRequirements.gdc == Dependency.any);
 	assert(rec.ddoxFilterArgs == ["-arg1", "-arg2", "-arg3"], rec.ddoxFilterArgs.to!string);
 	assert(rec.ddoxTool == "ddoxtool");
 	assert(rec.buildSettings.dependencies.length == 2);
diff --git a/test/issue1531-toolchain-requirements.sh b/test/issue1531-toolchain-requirements.sh
index 77bf5f4..c384198 100755
--- a/test/issue1531-toolchain-requirements.sh
+++ b/test/issue1531-toolchain-requirements.sh
@@ -91,7 +91,7 @@
 test_cl_req_fail ">$DC_VER"
 test_cl_req_pass "<=$DC_VER"
 test_cl_req_fail "<$DC_VER"
-test_cl_req_pass ">=$DC_VER|<$(($DC_VER_MAJ + 1))$DC_VER_REM"
+test_cl_req_pass ">=$DC_VER <$(($DC_VER_MAJ + 1))$DC_VER_REM"
 test_cl_req_pass "~>$DC_VER"
 test_cl_req_fail "~>$(($DC_VER_MAJ + 1))$DC_VER_REM"
 test_cl_req_fail no