diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 9b164e416af..ec8c80b2754 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -52,3 +52,5 @@ jobs:
             make -j4
             make install
             ctest --output-on-failure
+            cd ..
+            bash ./utils/scripts/check_installs.sh
diff --git a/.github/workflows/tests_minimal.yml b/.github/workflows/tests_minimal.yml
index 52f2e70e361..4bcec88c340 100644
--- a/.github/workflows/tests_minimal.yml
+++ b/.github/workflows/tests_minimal.yml
@@ -37,3 +37,5 @@ jobs:
             make -j4
             make install
             ctest --output-on-failure
+            cd ..
+            bash ./utils/scripts/check_installs.sh
diff --git a/.github/workflows/tests_minimal_kokkos.yml b/.github/workflows/tests_minimal_kokkos.yml
index 5038f44b4b1..9c880b9ffa3 100644
--- a/.github/workflows/tests_minimal_kokkos.yml
+++ b/.github/workflows/tests_minimal_kokkos.yml
@@ -37,3 +37,5 @@ jobs:
             make -j4
             make install
             ctest --output-on-failure
+            cd ..
+            bash ./utils/scripts/check_installs.sh
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 69870046758..fbef9f2d111 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,10 +5,11 @@
 ### Added (new features/APIs/variables/...)
 
 ### Fixed (Repair bugs, etc)
-
+- [[PR647]](https://github.com/lanl/singularity-eos/pull/647) Add missing headers to the registration in singularity-eos/CMakeLists.txt
 ### Changed (changing behavior/API/variables/...)
 
 ### Infrastructure (changes irrelevant to downstream codes)
+- [[PR649]](https://github.com/lanl/singularity-eos/pull/649) Add checks that all header files are installed properly.
 
 ### Deprecated (soon to be removed behavior/API/variables/...)
 
diff --git a/singularity-eos/CMakeLists.txt b/singularity-eos/CMakeLists.txt
index 30a1fdea759..9cb3f8693ff 100644
--- a/singularity-eos/CMakeLists.txt
+++ b/singularity-eos/CMakeLists.txt
@@ -28,6 +28,8 @@ register_headers(
     base/spiner_table_utils.hpp
     base/constants.hpp
     base/eos_error.hpp
+    base/eos_concepts.hpp
+    base/finite_diff.hpp
     eos/default_variant.hpp
     eos/eos_variant.hpp
     eos/eos_stellar_collapse.hpp
@@ -39,6 +41,7 @@ register_headers(
     eos/eos_spiner_rho_sie.hpp
     eos/eos_spiner_rho_temp.hpp
     eos/eos_spiner_common.hpp
+    eos/eos_spiner_construction.hpp
     eos/eos_spiner_sie_transforms.hpp
     eos/eos_davis.hpp
     eos/eos_gruneisen.hpp
diff --git a/singularity-utils/singularity-utils/fast-math/logs.hpp b/singularity-utils/singularity-utils/fast-math/logs.hpp
index 609c2d3b495..8639238e770 100644
--- a/singularity-utils/singularity-utils/fast-math/logs.hpp
+++ b/singularity-utils/singularity-utils/fast-math/logs.hpp
@@ -1,3 +1,4 @@
+
 //======================================================================
 // © 2021-2026. Triad National Security, LLC. All rights reserved.  This
 // program was produced under U.S. Government contract 89233218CNA000001
@@ -115,7 +116,7 @@ constexpr std::int64_t one = 1;
 // as_int(1.0) == 2^62 - 2^52
 constexpr std::int64_t one_as_int = (one << 62) - (one << 52);
 // 1./static_cast<double>(as_int(2.0) - as_int(1.0)) == 2^-52
-constexpr double scale_down = 2.22044604925031e-16;
+constexpr double scale_down = 2.220446049250313e-16;
 // as_int(2.0) - as_int(1.0) = 2^52, but note the type
 constexpr double scale_up = (one << 52);
 // 2^52 - 1
diff --git a/utils/scripts/check_installs.sh b/utils/scripts/check_installs.sh
new file mode 100755
index 00000000000..8362c46d826
--- /dev/null
+++ b/utils/scripts/check_installs.sh
@@ -0,0 +1,67 @@
+#!/bin/bash
+
+#------------------------------------------------------------------------------
+# © 2021-2026. Triad National Security, LLC. All rights reserved.  This
+# program was produced under U.S. Government contract 89233218CNA000001
+# for Los Alamos National Laboratory (LANL), which is operated by Triad
+# National Security, LLC for the U.S.  Department of Energy/National
+# Nuclear Security Administration. All rights in the program are
+# reserved by Triad National Security, LLC, and the U.S. Department of
+# Energy/National Nuclear Security Administration. The Government is
+# granted for itself and others acting on its behalf a nonexclusive,
+# paid-up, irrevocable worldwide license in this material to reproduce,
+# prepare derivative works, distribute copies to the public, perform
+# publicly and display publicly, and to permit others to do so.
+#------------------------------------------------------------------------------
+
+# This file generated with the assistance of generative AI
+
+# Report singularity-eos headers that are missing install logic.
+#
+# Every .hpp under singularity-eos/ is meant to be installed, which means it
+# must appear as an argument to a register_headers(...) call in some
+# CMakeLists.txt (see cmake/plugins.cmake). A header that is never registered
+# is silently left out of the install. This script flags any such header so
+# it can be wired into CI as a guard (non-zero exit when any are found).
+
+set -euo pipefail
+
+# Move to the repo root (two levels up from utils/scripts/).
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(cd "${SCRIPT_DIR}/../.." && pwd)"
+cd "${REPO_ROOT}"
+
+# Directory whose headers must all be installed.
+HEADER_ROOT="singularity-eos"
+
+# Collect the text of every CMakeLists.txt so we can search registrations.
+CMAKE_FILES=$(find . -name CMakeLists.txt -not -path './build/*' -not -path './.git/*')
+
+missing=0
+for f in $(find "${HEADER_ROOT}" -name '*.hpp' | sed "s|^${HEADER_ROOT}/||" | sort); do
+  base=$(basename "$f")
+  # A header is considered registered if either its path relative to the
+  # header root, or just its file name, appears in a CMakeLists.txt. The
+  # register_headers() paths are relative to the calling CMakeLists.txt, so
+  # matching on the basename keeps this robust without re-implementing
+  # CMake's path resolution.
+  if ! grep -rqF "$f" ${CMAKE_FILES} && ! grep -rqF "$base" ${CMAKE_FILES}; then
+    if [ "$missing" -eq 0 ]; then
+      echo "Headers missing register_headers() install logic:"
+    fi
+    echo "  ${HEADER_ROOT}/$f"
+    missing=$((missing + 1))
+  fi
+done
+
+if [ "$missing" -eq 0 ]; then
+  echo "OK: every ${HEADER_ROOT} header has register_headers() install logic."
+  exit 0
+fi
+
+echo ""
+echo "${missing} header(s) have no register_headers call."
+echo "Add each to a register_headers(...) call in the appropriate CMakeLists.txt"
+echo "(with the matching build condition if it is only needed under an option),"
+echo "or exclude it deliberately."
+exit 1