diff --git a/index/li/libblas/libblas-external.toml b/index/li/libblas/libblas-external.toml
index 1c731185..b6df2142 100644
--- a/index/li/libblas/libblas-external.toml
+++ b/index/li/libblas/libblas-external.toml
@@ -9,5 +9,6 @@ maintainers-logins = ["simonjwright"]
 [[external]]
 kind="system"
 [external.origin."case(distribution)"]
+"macos" = []
 "debian|ubuntu" = ["libblas-dev"]
-# "msys2" = ["mingw-w64-x86_64-openblas"]
+"msys2" = ["mingw-w64-x86_64-lapack"]
diff --git a/index/li/liblapack/liblapack-external.toml b/index/li/liblapack/liblapack-external.toml
index 411f0b70..4db4cee1 100644
--- a/index/li/liblapack/liblapack-external.toml
+++ b/index/li/liblapack/liblapack-external.toml
@@ -9,5 +9,6 @@ maintainers-logins = ["simonjwright"]
 [[external]]
 kind="system"
 [external.origin."case(distribution)"]
+"macos" = []
 "debian|ubuntu" = ["liblapack-dev"]
-# "msys2" = ["mingw-w64-x86_64-lapack"]
+"msys2" = ["mingw-w64-x86_64-lapack"]