diff --git a/src/minimizer/bfgs_minimize.cu b/src/minimizer/bfgs_minimize.cu
index e240eecd..b40cfa1c 100644
--- a/src/minimizer/bfgs_minimize.cu
+++ b/src/minimizer/bfgs_minimize.cu
@@ -908,11 +908,13 @@ __global__ void updateDGradKernel(const double  gradTol,
   double blockMax = cub::BlockReduce<double, 128>(tempStorage).Reduce(localMax, cubMax());
 
   if (idxWithinSystem == 0) {
-    // Matches RDKit's signed-energy convergence denominator in ForceField::minimize.
-    // Negative-energy geometries can clamp this to 1, artificially tightening the
-    // check — but fixing it unconditionally diverges from reference behavior.
-    // TODO: file upstream RDKit bug; gate fix on RDKit version once merged there.
-    const double term = max(energies[sysIdx] * gradScales[sysIdx], 1.0);
+    // rdkit/rdkit#9298 (merged RDKit 2026.03) fixed the signed-energy denominator bug:
+    // raw negative energy clamped the denominator to 1, artificially tightening gradTol.
+    // Use |energy| when linked against a fixed RDKit; keep signed otherwise for parity.
+    constexpr bool kRdkitHasGradDenomFix =
+      RDKIT_VERSION_MAJOR > 2026 || (RDKIT_VERSION_MAJOR == 2026 && RDKIT_VERSION_MINOR >= 3);
+    const double energyMag = kRdkitHasGradDenomFix ? fabs(energies[sysIdx]) : energies[sysIdx];
+    const double term      = max(energyMag * gradScales[sysIdx], 1.0);
     blockMax /= term;
     if (blockMax < gradTol) {
       // Converged
diff --git a/src/minimizer/bfgs_minimize_permol_kernels.cu b/src/minimizer/bfgs_minimize_permol_kernels.cu
index cdd463cb..ee4b77d7 100644
--- a/src/minimizer/bfgs_minimize_permol_kernels.cu
+++ b/src/minimizer/bfgs_minimize_permol_kernels.cu
@@ -292,7 +292,12 @@ __device__ void updateDGrad(const int
   float blockMax = cub::BlockReduce<double, BLOCK_SIZE>(tempStorage).Reduce(localMax, cubMax());
 
   if (threadIdx.x == 0) {
-    const float term = max(energy * gradScale, 1.0);
+    // rdkit/rdkit#9298 (merged RDKit 2026.03): use |energy| to avoid clamping the
+    // denominator to 1 when energy is negative; match signed behavior on older RDKit.
+    constexpr bool kRdkitHasGradDenomFix =
+      RDKIT_VERSION_MAJOR > 2026 || (RDKIT_VERSION_MAJOR == 2026 && RDKIT_VERSION_MINOR >= 3);
+    const double energyMag = kRdkitHasGradDenomFix ? fabs(energy) : energy;
+    const float  term      = max(energyMag * gradScale, 1.0);
     blockMax /= term;
     if (blockMax < gradTol) {
       converged = true;