diff --git a/src/Mod/Import/Gui/AppImportGuiPy.cpp b/src/Mod/Import/Gui/AppImportGuiPy.cpp
index 620c5b77d2..7fe080618e 100644
--- a/src/Mod/Import/Gui/AppImportGuiPy.cpp
+++ b/src/Mod/Import/Gui/AppImportGuiPy.cpp
@@ -411,7 +411,13 @@ private:
             }
 
             ImportOCAFExt ocaf(hDoc, pcDoc, file.fileNamePure());
+            // We must recompute the doc before loading shapes as they are going to be
+            // inserted into the document and computed at the same time so we are going to
+            // purge the document before recomputing it to clear it and settle it in the proper
+            // way. This is drastically improving STEP rendering time on complex STEP files.
+            pcDoc->recompute();
             ocaf.loadShapes();
+            pcDoc->purgeTouched();
             pcDoc->recompute();
             hApp->Close(hDoc);
         }