diff --git a/slsDetectorCalibration/interpolatingDetector.h b/slsDetectorCalibration/interpolatingDetector.h
index 48d1508b2..81fdaf5c4 100644
--- a/slsDetectorCalibration/interpolatingDetector.h
+++ b/slsDetectorCalibration/interpolatingDetector.h
@@ -51,6 +51,7 @@ class interpolatingDetector : public singlePhotonDetector {
         // cout << "**"<< xmin << " " << xmax << " " << ymin << " " << ymax <<
         // endl;
         fi = new pthread_mutex_t;
+        pthread_mutex_init(fi, NULL);
     };
 
     interpolatingDetector(interpolatingDetector *orig)
diff --git a/slsDetectorCalibration/singlePhotonDetector.h b/slsDetectorCalibration/singlePhotonDetector.h
index f9a409b89..07b89b5d6 100644
--- a/slsDetectorCalibration/singlePhotonDetector.h
+++ b/slsDetectorCalibration/singlePhotonDetector.h
@@ -63,6 +63,7 @@ class singlePhotonDetector : public analogDetector<uint16_t> {
           quad(UNDEFINED_QUADRANT), tot(0), quadTot(0) {
 
         fm = new pthread_mutex_t;
+        pthread_mutex_init(fm, NULL);
 
         eventMask = new eventType *[ny];
         //  val=new double*[ny];