diff --git a/src/libslic3r/SLA/SLASupportTree.cpp b/src/libslic3r/SLA/SLASupportTree.cpp
index 5e0ac1c95..99f7bc8b3 100644
--- a/src/libslic3r/SLA/SLASupportTree.cpp
+++ b/src/libslic3r/SLA/SLASupportTree.cpp
@@ -85,7 +85,7 @@ using Portion = std::tuple<double, double>;
 
 // Set this to true to enable full parallelism in this module.
 // Only the well tested parts will be concurrent if this is set to false.
-const constexpr bool USE_FULL_CONCURRENCY = true;
+const constexpr bool USE_FULL_CONCURRENCY = false;
 
 template<bool> struct _ccr {};
 
@@ -1194,7 +1194,7 @@ class SLASupportTree::Algorithm {
         // Now a and b vectors are perpendicular to v and to each other.
         // Together they define the plane where we have to iterate with the
         // given angles in the 'phis' vector
-        ccr_seq::enumerate(phis.begin(), phis.end(),
+        ccr_par::enumerate(phis.begin(), phis.end(),
                            [&hits, &m, sd, r_pin, r_back, s, a, b, c]
                            (double phi, size_t i)
         {
@@ -1297,7 +1297,7 @@ class SLASupportTree::Algorithm {
         // Hit results
         std::array<HitResult, SAMPLES> hits;
 
-        ccr_seq::enumerate(phis.begin(), phis.end(),
+        ccr_par::enumerate(phis.begin(), phis.end(),
                            [&m, a, b, sd, dir, r, s, ins_check, &hits]
                            (double phi, size_t i)
         {