diff --git a/src/libslic3r/SLA/SLABasePool.hpp b/src/libslic3r/SLA/SLABasePool.hpp
index 07a76265a..62c4971eb 100644
--- a/src/libslic3r/SLA/SLABasePool.hpp
+++ b/src/libslic3r/SLA/SLABasePool.hpp
@@ -7,11 +7,12 @@
 namespace Slic3r {
 
 class ExPolygon;
+using ExPolygons = std::vector<ExPolygon>;
+
 class TriangleMesh;
 
 namespace sla {
 
-using ExPolygons = std::vector<ExPolygon>;
 using ThrowOnCancel = std::function<void(void)>;
 
 /// Calculate the polygon representing the silhouette from the specified height
diff --git a/src/libslic3r/SLAPrint.cpp b/src/libslic3r/SLAPrint.cpp
index 9d35a4a34..5e3191b6e 100644
--- a/src/libslic3r/SLAPrint.cpp
+++ b/src/libslic3r/SLAPrint.cpp
@@ -565,7 +565,7 @@ void SLAPrint::process()
             if(!po.m_config.supports_enable.getBool()) elevation = 0;
             sla::PoolConfig pcfg(wt, h, md, er);
 
-            sla::ExPolygons bp;
+            ExPolygons bp;
             double pad_h = sla::get_pad_elevation(pcfg);
             auto&& trmesh = po.transformed_mesh();