diff --git a/rtengine/FTblockDN.cc b/rtengine/FTblockDN.cc
index a556e1f4e..73c23a4cf 100644
--- a/rtengine/FTblockDN.cc
+++ b/rtengine/FTblockDN.cc
@@ -258,7 +258,10 @@ namespace rtengine {
         // Calculate number of tiles. If less than omp_get_max_threads(), then limit num_threads to number of tiles
         int numtiles = numtiles_W * numtiles_H;
         int numthreads = MIN(numtiles,omp_get_max_threads());
-        if(options.rgbDenoiseThreadLimit > 0) numthreads = MIN(numthreads,options.rgbDenoiseThreadLimit);
+        if(options.rgbDenoiseThreadLimit > 0) numthreads = MIN(numthreads,options.rgbDenoiseThreadLimit);
+        // Issue 1887, overide setting of 1, if more than one thread is available. This way the inner omp-directives should become inactive
+        if(numthreads == 1 && omp_get_max_threads() > 1)
+			numthreads = 2;
 #pragma omp parallel num_threads(numthreads)
 #endif
         {