diff --git a/RecoTracker/MkFitCore/BuildFile.xml b/RecoTracker/MkFitCore/BuildFile.xml
index 4caccf93b36f7..7ccecdb78f361 100644
--- a/RecoTracker/MkFitCore/BuildFile.xml
+++ b/RecoTracker/MkFitCore/BuildFile.xml
@@ -2,7 +2,6 @@
 <use name="json"/>
 <use name="tbb"/>
 <flags CXXFLAGS="-fopenmp-simd"/>
-<flags CXXFLAGS="-ffast-math"/>
 <flags ADD_SUBDIR="1"/>
 <export>
   <lib name="RecoTrackerMkFitCore"/>
diff --git a/RecoTracker/MkFitCore/src/PropagationMPlex.cc b/RecoTracker/MkFitCore/src/PropagationMPlex.cc
index 648629b7a9941..13d57565072c7 100644
--- a/RecoTracker/MkFitCore/src/PropagationMPlex.cc
+++ b/RecoTracker/MkFitCore/src/PropagationMPlex.cc
@@ -592,15 +592,15 @@ namespace mkfit {
 
   //==============================================================================
 
-  void __attribute__((optimize("math-errno"))) propagateHelixToZMPlex(const MPlexLS& inErr,
-                                                                      const MPlexLV& inPar,
-                                                                      const MPlexQI& inChg,
-                                                                      const MPlexQF& msZ,
-                                                                      MPlexLS& outErr,
-                                                                      MPlexLV& outPar,
-                                                                      const int N_proc,
-                                                                      const PropagationFlags pflags,
-                                                                      const MPlexQI* noMatEffPtr) {
+  void propagateHelixToZMPlex(const MPlexLS& inErr,
+                              const MPlexLV& inPar,
+                              const MPlexQI& inChg,
+                              const MPlexQF& msZ,
+                              MPlexLS& outErr,
+                              MPlexLV& outPar,
+                              const int N_proc,
+                              const PropagationFlags pflags,
+                              const MPlexQI* noMatEffPtr) {
     // debug = true;
 
     outErr = inErr;