diff --git a/toolchain/lib/builder.lua b/toolchain/lib/builder.lua
index 55c5d4d..95019be 100644
--- a/toolchain/lib/builder.lua
+++ b/toolchain/lib/builder.lua
@@ -243,7 +243,16 @@ function builder.run_build(recipe, source_dir, stage_dir, opts)
   end
 
   if bs == "autotools" then
-    run("./configure --prefix=/usr" .. args_str)
+    -- Some projects ship a capitalized Configure instead of autoconf's configure.
+    local config_script = "configure"
+    if not path.exists(path.join(source_dir, "configure")) then
+      if path.exists(path.join(source_dir, "Configure")) then
+        config_script = "Configure"
+      else
+        error(("no configure script found in %s (looked for ./configure and ./Configure)"):format(source_dir), 0)
+      end
+    end
+    run("./" .. config_script .. " --prefix=/usr" .. args_str)
     run("make -j" .. njobs)
     run("make install DESTDIR=" .. path.quote(stage_dir))