diff --git a/.ci_support/linux_64_.yaml b/.ci_support/linux_64_.yaml
index 54ddec2..7b27efb 100644
--- a/.ci_support/linux_64_.yaml
+++ b/.ci_support/linux_64_.yaml
@@ -40,7 +40,7 @@ python:
 r_base:
 - '4.3'
 spdlog:
-- '1.14'
+- '1.15'
 target_platform:
 - linux-64
 zip_keys:
diff --git a/.ci_support/migrations/spdlog115.yaml b/.ci_support/migrations/spdlog115.yaml
new file mode 100644
index 0000000..8fb50aa
--- /dev/null
+++ b/.ci_support/migrations/spdlog115.yaml
@@ -0,0 +1,9 @@
+__migrator:
+  build_number: 1
+  commit_message: Rebuild for spdlog 1.15
+  kind: version
+  migration_number: 1
+migrator_ts: 1731195190.0405502
+spdlog:
+- '1.15'
+
diff --git a/.ci_support/osx_64_.yaml b/.ci_support/osx_64_.yaml
index c85ba59..4a8413c 100644
--- a/.ci_support/osx_64_.yaml
+++ b/.ci_support/osx_64_.yaml
@@ -1,7 +1,7 @@
 MACOSX_DEPLOYMENT_TARGET:
 - '11.0'
 MACOSX_SDK_VERSION:
-- '11.0'
+- '13.3'
 c_compiler:
 - clang
 c_compiler_version:
@@ -42,7 +42,7 @@ python:
 r_base:
 - '4.3'
 spdlog:
-- '1.14'
+- '1.15'
 target_platform:
 - osx-64
 zip_keys:
diff --git a/.ci_support/osx_arm64_.yaml b/.ci_support/osx_arm64_.yaml
index e2880da..464712c 100644
--- a/.ci_support/osx_arm64_.yaml
+++ b/.ci_support/osx_arm64_.yaml
@@ -42,7 +42,7 @@ python:
 r_base:
 - '4.3'
 spdlog:
-- '1.14'
+- '1.15'
 target_platform:
 - osx-arm64
 zip_keys:
diff --git a/recipe/build-libtiledbsoma.sh b/recipe/build-libtiledbsoma.sh
index 12d4f4f..5d50926 100644
--- a/recipe/build-libtiledbsoma.sh
+++ b/recipe/build-libtiledbsoma.sh
@@ -2,6 +2,9 @@
 
 set -exo pipefail
 
+# Clear default compiler flags
+export CXXFLAGS=${CXXFLAGS//"-fvisibility-inlines-hidden"/}
+
 mkdir libtiledbsoma-build && cd libtiledbsoma-build
 
 cmake \
diff --git a/recipe/build-r-tiledbsoma.sh b/recipe/build-r-tiledbsoma.sh
index ffb435e..b3a3247 100644
--- a/recipe/build-r-tiledbsoma.sh
+++ b/recipe/build-r-tiledbsoma.sh
@@ -4,21 +4,29 @@ set -ex
 
 cd apis/r
 
+# Clear default compiler flags
+export CXXFLAGS=${CXXFLAGS//"-fvisibility-inlines-hidden"/}
+
 export DISABLE_AUTOBREW=1
 
 # https://github.com/conda-forge/r-tiledb-feedstock/commit/29cb6816636e7b5b58545e1407a8f0c29ff9dc39
-if [[ $target_platform  == osx-64 ]]; then
+if [[ $target_platform == osx-* ]]; then
   export NN_CXX_ORIG=$CXX
   export NN_CC_ORIG=$CC
   export CXX=$RECIPE_DIR/cxx_wrap.sh
   export CC=$RECIPE_DIR/cc_wrap.sh
-  mkdir -p ~/.R
-  echo CC=$RECIPE_DIR/cc_wrap.sh > ~/.R/Makevars
-  echo CXX=$RECIPE_DIR/cxx_wrap.sh >> ~/.R/Makevars
-  echo CXX17=$RECIPE_DIR/cxx_wrap.sh >> ~/.R/Makevars
+  export CXX20=$RECIPE_DIR/cxx_wrap.sh
 fi
 
-export CXX17FLAGS="-Wno-deprecated-declarations -Wno-deprecated"
+export CXX="$CXX -std=c++20 -fPIC"
+export CXX20="$CXX"
+
+mkdir -p ~/.R
+echo CC="$CC" > ~/.R/Makevars
+echo CXX="$CXX" >> ~/.R/Makevars
+echo CXX20="$CXX20" >> ~/.R/Makevars
+
+export CXX20FLAGS="-Wno-deprecated-declarations -Wno-deprecated"
 
 # https://conda-forge.org/docs/maintainer/knowledge_base/#newer-c-features-with-old-sdk
 if [[ $target_platform == osx-*  ]]; then
diff --git a/recipe/build-tiledbsoma-py.sh b/recipe/build-tiledbsoma-py.sh
index a55c068..1cb92ce 100644
--- a/recipe/build-tiledbsoma-py.sh
+++ b/recipe/build-tiledbsoma-py.sh
@@ -4,6 +4,9 @@ set -ex
 
 cd apis/python
 
+# Clear default compiler flags
+export CXXFLAGS=${CXXFLAGS//"-fvisibility-inlines-hidden"/}
+
 echo
 echo "PKG_VERSION IS <<$PKG_VERSION>>"
 echo
diff --git a/recipe/cc_wrap.sh b/recipe/cc_wrap.sh
index a2bfc0c..30a8464 100755
--- a/recipe/cc_wrap.sh
+++ b/recipe/cc_wrap.sh
@@ -1,4 +1,4 @@
 #!/bin/sh
 
-args="${@##-mmacosx-version-min=10.9*}"
-$NN_CC_ORIG $args -mmacosx-version-min=11.0
+args="${@##-mmacosx-version-min=13.3*}"
+$NN_CC_ORIG $args -mmacosx-version-min=13.3
diff --git a/recipe/conda_build_config.yaml b/recipe/conda_build_config.yaml
index 1e171f6..4418c92 100644
--- a/recipe/conda_build_config.yaml
+++ b/recipe/conda_build_config.yaml
@@ -1,7 +1,7 @@
 # https://conda-forge.org/docs/maintainer/knowledge_base/#requiring-newer-macos-sdks
 # https://conda-forge.org/news/2024/03/24/stdlib-migration/
-MACOSX_SDK_VERSION:  # [osx and x86_64]
-  - 11.0            # [osx and x86_64]
+MACOSX_SDK_VERSION:            # [osx and x86_64]
+  - 13.3                       # [osx and x86_64]
 c_stdlib_version:              # [osx and x86_64]
   - 11.0                       # [osx and x86_64]
 channel_sources:
diff --git a/recipe/cxx_wrap.sh b/recipe/cxx_wrap.sh
index 5d9def4..560946d 100755
--- a/recipe/cxx_wrap.sh
+++ b/recipe/cxx_wrap.sh
@@ -1,4 +1,4 @@
 #!/bin/sh
 
-args="${@##-mmacosx-version-min=10.9*}"
-$NN_CXX_ORIG $args -mmacosx-version-min=11.0
+args="${@##-mmacosx-version-min=13.3*}"
+$NN_CXX_ORIG $args -mmacosx-version-min=13.3
diff --git a/recipe/meta.yaml b/recipe/meta.yaml
index 2228d39..1059f55 100644
--- a/recipe/meta.yaml
+++ b/recipe/meta.yaml
@@ -17,8 +17,12 @@ package:
 
 # Post-tag real thing:
 source:
-  url: https://github.com/single-cell-data/TileDB-SOMA/archive/{{ version }}.tar.gz
-  sha256: {{ sha256 }}
+  # url: https://github.com/single-cell-data/TileDB-SOMA/archive/{{ version }}.tar.gz
+  # sha256: {{ sha256 }}
+  # Troubleshoot C++20 by pulling latest from main (just like the nightly builds)
+  git_url: https://github.com/single-cell-data/TileDB-SOMA.git
+  git_rev: main
+  git_depth: -1
 
 # Pre-tag canary "will Conda be green if we release":
 #source: