diff --git a/src/emu/netlist/solver/vector_base.h b/src/emu/netlist/solver/vector_base.h
index 534c9226e89..bacf202c235 100644
--- a/src/emu/netlist/solver/vector_base.h
+++ b/src/emu/netlist/solver/vector_base.h
@@ -35,7 +35,9 @@ inline void vec_set (const std::size_t n, const double &scalar, double * RESTRIC
 	for ( std::size_t i = 0; i < n; i++ )
 		result[i] = scalar;
 }
+#if HAS_OPENMP
 #include "omp.h"
+#endif
 inline double vecmult (const std::size_t n, const double * RESTRICT a1, const double * RESTRICT a2 )
 {