diff --git a/gtsam/inference/Conditional-inst.h b/gtsam/inference/Conditional-inst.h
index 1b439649e..8445b74bd 100644
--- a/gtsam/inference/Conditional-inst.h
+++ b/gtsam/inference/Conditional-inst.h
@@ -63,4 +63,22 @@ double Conditional<FACTOR, DERIVEDCONDITIONAL>::normalizationConstant() const {
   return std::exp(logNormalizationConstant());
 }
 
+/* ************************************************************************* */
+template <class FACTOR, class DERIVEDCONDITIONAL>
+template <class VALUES>
+bool Conditional<FACTOR, DERIVEDCONDITIONAL>::CheckInvariants(
+    const DERIVEDCONDITIONAL& conditional, const VALUES& values) {
+  const double probability = conditional.evaluate(values);
+  if (probability < 0.0 || probability > 1.0)
+    return false;  // probability is not in [0,1]
+  const double logProb = conditional.logProbability(values);
+  if (std::abs(probability - std::exp(logProb)) > 1e-9)
+    return false;  // logProb is not consistent with probability
+  const double expected =
+      conditional.logNormalizationConstant() - conditional.error(values);
+  if (std::abs(logProb - expected) > 1e-9)
+    return false;  // logProb is not consistent with error
+  return true;
+}
+
 }  // namespace gtsam
diff --git a/gtsam/inference/Conditional.h b/gtsam/inference/Conditional.h
index bba4c7bd5..b4b1080aa 100644
--- a/gtsam/inference/Conditional.h
+++ b/gtsam/inference/Conditional.h
@@ -181,6 +181,10 @@ namespace gtsam {
     /** Mutable iterator pointing past the last parent key. */
     typename FACTOR::iterator endParents() { return asFactor().end(); }
 
+    template <class VALUES>
+    static bool CheckInvariants(const DERIVEDCONDITIONAL& conditional,
+                                const VALUES& values);
+
     /// @}
 
   private:
diff --git a/gtsam/linear/tests/testGaussianConditional.cpp b/gtsam/linear/tests/testGaussianConditional.cpp
index 12c668c25..0479ce9a1 100644
--- a/gtsam/linear/tests/testGaussianConditional.cpp
+++ b/gtsam/linear/tests/testGaussianConditional.cpp
@@ -135,23 +135,6 @@ static const auto unitPrior =
                       noiseModel::Isotropic::Sigma(1, sigma));
 }  // namespace density
 
-/* ************************************************************************* */
-template <class VALUES>
-bool checkInvariants(const GaussianConditional& conditional,
-                     const VALUES& values) {
-  const double probability = conditional.evaluate(values);
-  if (probability < 0.0 || probability > 1.0)
-    return false;  // probability is not in [0,1]
-  const double logProb = conditional.logProbability(values);
-  if (std::abs(probability - std::exp(logProb)) > 1e-9)
-    return false;  // logProb is not consistent with probability
-  const double expected =
-      conditional.logNormalizationConstant() - conditional.error(values);
-  if (std::abs(logProb - expected) > 1e-9)
-    return false;  // logProb is not consistent with error
-  return true;
-}
-
 /* ************************************************************************* */
 // Check that the evaluate function matches direct calculation with R.
 TEST(GaussianConditional, Evaluate1) {
@@ -174,8 +157,9 @@ TEST(GaussianConditional, Evaluate1) {
 
   // Check Invariants at the mean and a different value
   for (auto vv : {mean, VectorValues{{key, Vector1(4)}}}) {
-    EXPECT(checkInvariants(density::unitPrior, vv));
-    EXPECT(checkInvariants(density::unitPrior, HybridValues{vv, {}, {}}));
+    EXPECT(GaussianConditional::CheckInvariants(density::unitPrior, vv));
+    EXPECT(GaussianConditional::CheckInvariants(density::unitPrior,
+                                                HybridValues{vv, {}, {}}));
   }
 
   // Let's numerically integrate and see that we integrate to 1.0.
@@ -206,8 +190,9 @@ TEST(GaussianConditional, Evaluate2) {
 
   // Check Invariants at the mean and a different value
   for (auto vv : {mean, VectorValues{{key, Vector1(4)}}}) {
-    EXPECT(checkInvariants(density::widerPrior, vv));
-    EXPECT(checkInvariants(density::widerPrior, HybridValues{vv, {}, {}}));
+    EXPECT(GaussianConditional::CheckInvariants(density::widerPrior, vv));
+    EXPECT(GaussianConditional::CheckInvariants(density::widerPrior,
+                                                HybridValues{vv, {}, {}}));
   }
 
   // Let's numerically integrate and see that we integrate to 1.0.
@@ -422,8 +407,9 @@ TEST(GaussianConditional, FromMeanAndStddev) {
 
   // Check Invariants for both conditionals
   for (auto conditional : {conditional1, conditional2}) {
-    EXPECT(checkInvariants(conditional, values));
-    EXPECT(checkInvariants(conditional, HybridValues{values, {}, {}}));
+    EXPECT(GaussianConditional::CheckInvariants(conditional, values));
+    EXPECT(GaussianConditional::CheckInvariants(conditional,
+                                                HybridValues{values, {}, {}}));
   }
 }