diff --git a/crypto/libring.Windows.vcxproj b/crypto/libring.Windows.vcxproj
index 7be9948c2b..dccb30f7af 100644
--- a/crypto/libring.Windows.vcxproj
+++ b/crypto/libring.Windows.vcxproj
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="GenerateAsm;Build" ToolsVersion="14.0"
+    xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup Label="Globals">
     <ProjectGuid>{F4C0A1B6-5E09-41C8-8242-3E1F6762FB18}</ProjectGuid>
     <ProjectName>libring.Windows</ProjectName>
@@ -75,24 +76,6 @@
     <PerlAsm Include="sha/asm/sha256-586.pl" />
     <PerlAsm Include="sha/asm/sha512-586.pl" />
   </ItemGroup>
-  <ItemDefinitionGroup Condition="'$(ProcessorArchitecture)' == 'x86'">
-    <!-- XXX: There's almost definitely a way to defiune the PerlAsm task to
-         compute this automatically, but for now we do it manually. -->
-    <Lib>
-      <AdditionalDependencies>
-        $(IntDir)aes-586.obj;
-        $(IntDir)aesni-x86.obj;
-        $(IntDir)vpaes-x86.obj;
-        $(IntDir)x86-mont.obj;
-        $(IntDir)chacha-x86.obj;
-        $(IntDir)ecp_nistz256-x86.obj;
-        $(IntDir)ghash-x86.obj;
-        $(IntDir)poly1305-x86.obj;
-        $(IntDir)sha256-586.obj;
-        $(IntDir)sha512-586.obj;
-      </AdditionalDependencies>
-    </Lib>
-  </ItemDefinitionGroup>
   <ItemGroup Condition="'$(ProcessorArchitecture)' == 'amd64'">
     <PerlAsm Include="aes/asm/aes-x86_64.pl" />
     <PerlAsm Include="aes/asm/aesni-x86_64.pl" />
@@ -116,29 +99,6 @@
       <AdditionalDependencies>sha/asm/sha-x86_64.pl</AdditionalDependencies>
     </PerlAsm>
   </ItemGroup>
-  <ItemDefinitionGroup Condition="'$(ProcessorArchitecture)' == 'amd64'">
-    <!-- XXX: There's almost definitely a way to defiune the PerlAsm task to
-         compute this automatically, but for now we do it manually. -->
-    <Lib>
-      <AdditionalDependencies>
-        $(IntDir)aes-x86_64.obj;
-        $(IntDir)aesni-x86_64.obj;
-        $(IntDir)bsaes-x86_64.obj;
-        $(IntDir)chacha-x86_64.obj;
-        $(IntDir)vpaes-x86_64.obj;
-        $(IntDir)rsaz-avx2.obj;
-        $(IntDir)x86_64-mont.obj;
-        $(IntDir)x86_64-mont5.obj;
-        $(IntDir)ecp_nistz256-x86_64.obj;
-        $(IntDir)p256-x86_64-asm.obj;
-        $(IntDir)aesni-gcm-x86_64.obj;
-        $(IntDir)ghash-x86_64.obj;
-        $(IntDir)poly1305-x86_64.obj;
-        $(IntDir)sha256-x86_64.obj;
-        $(IntDir)sha512-x86_64.obj;
-      </AdditionalDependencies>
-    </Lib>
-  </ItemDefinitionGroup>
   <ItemDefinitionGroup>
     <ClCompile>
       <AdditionalIncludeDirectories>%(AdditionalIncludeDirectories);..\include</AdditionalIncludeDirectories>
diff --git a/mk/perlasm-msbuild.targets b/mk/perlasm-msbuild.targets
index ed5bce4a2a..f6e5abeb46 100644
--- a/mk/perlasm-msbuild.targets
+++ b/mk/perlasm-msbuild.targets
@@ -23,10 +23,24 @@
     <MakeDir Directories="$(IntDir)"/>
   </Target>
 
+  <PropertyGroup>
+    <ComputeLibInputsTargets>
+      $(ComputeLibInputsTargets);
+      ComputeGenerateAsmOutput;
+    </ComputeLibInputsTargets>
+  </PropertyGroup>
+
+  <Target Name="ComputeGenerateAsmOutput">
+    <ItemGroup>
+      <Lib Include="$(IntDir)%(PerlAsm.Filename).obj" />
+    </ItemGroup>
+  </Target>
+
+  <!-- Because this uses `%(PerlAsm.Identity)`, it will be invoked for each
+       <PerlAsm> item. -->
   <Target
       Name="GenerateAsm"
       DependsOnTargets="CreateIntDir"
-      BeforeTargets="ClCompile"
       Inputs="%(PerlAsm.Identity);
               ../crypto/perlasm/arm-xlate.pl;
               ../crypto/perlasm/x86_64-xlate.pl;