diff --git a/src/IPhreeqc.cpp b/src/IPhreeqc.cpp
index df677105..5a86bd89 100644
--- a/src/IPhreeqc.cpp
+++ b/src/IPhreeqc.cpp
@@ -1106,6 +1106,10 @@ void IPhreeqc::do_run(const char* sz_routine, std::istream* pis, PFN_PRERUN_CALL
  *   run
  */
 		this->PhreeqcPtr->run_as_cells();
+/*
+ *   Calculate mixes
+ */
+		this->PhreeqcPtr->do_mixes();
 /*
  *   Copy
  */