diff --git a/Eigen/src/Core/arch/AVX/Complex.h b/Eigen/src/Core/arch/AVX/Complex.h
index 407300289..f891e0bc3 100644
--- a/Eigen/src/Core/arch/AVX/Complex.h
+++ b/Eigen/src/Core/arch/AVX/Complex.h
@@ -454,7 +454,15 @@ EIGEN_STRONG_INLINE Packet4cf plog<Packet4cf>(const Packet4cf& a) {
 
 template <>
 EIGEN_STRONG_INLINE Packet2cd pexp<Packet2cd>(const Packet2cd& a) {
+#ifdef EIGEN_VECTORIZE_AVX2
   return pexp_complex<Packet2cd>(a);
+#else
+  // Without AVX2, pexp_complex<Packet2cd> requires psincos_double<Packet4d> which needs
+  // 256-bit integer operations (Packet4l) not available on AVX-only targets.
+  // Process as two independent Packet1cd using the SSE implementation instead.
+  return Packet2cd(_mm256_insertf128_pd(_mm256_castpd128_pd256(pexp(Packet1cd(_mm256_castpd256_pd128(a.v))).v),
+                                        pexp(Packet1cd(_mm256_extractf128_pd(a.v, 1))).v, 1));
+#endif
 }
 
 template <>
diff --git a/Eigen/src/Core/arch/AVX/MathFunctions.h b/Eigen/src/Core/arch/AVX/MathFunctions.h
index f4f6794a1..965883c44 100644
--- a/Eigen/src/Core/arch/AVX/MathFunctions.h
+++ b/Eigen/src/Core/arch/AVX/MathFunctions.h
@@ -33,6 +33,24 @@ EIGEN_DOUBLE_PACKET_FUNCTION(cbrt, Packet4d)
 EIGEN_DOUBLE_PACKET_FUNCTION(sin, Packet4d)
 EIGEN_DOUBLE_PACKET_FUNCTION(cos, Packet4d)
 EIGEN_DOUBLE_PACKET_FUNCTION(tan, Packet4d)
+#else
+// Without AVX2, psincos_double<Packet4d> requires 256-bit integer operations (Packet4l)
+// that are not available. Process as two Packet2d halves using the SSE implementation.
+template <>
+EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet4d psin<Packet4d>(const Packet4d& x) {
+  return _mm256_insertf128_pd(_mm256_castpd128_pd256(psin(_mm256_castpd256_pd128(x))),
+                              psin(_mm256_extractf128_pd(x, 1)), 1);
+}
+template <>
+EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet4d pcos<Packet4d>(const Packet4d& x) {
+  return _mm256_insertf128_pd(_mm256_castpd128_pd256(pcos(_mm256_castpd256_pd128(x))),
+                              pcos(_mm256_extractf128_pd(x, 1)), 1);
+}
+template <>
+EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet4d ptan<Packet4d>(const Packet4d& x) {
+  return _mm256_insertf128_pd(_mm256_castpd128_pd256(ptan(_mm256_castpd256_pd128(x))),
+                              ptan(_mm256_extractf128_pd(x, 1)), 1);
+}
 #endif
 EIGEN_GENERIC_PACKET_FUNCTION(atan, Packet4d)
 EIGEN_GENERIC_PACKET_FUNCTION(exp2, Packet4d)