diff --git a/src/acs/call-funcs.cpp b/src/acs/call-funcs.cpp
index 17e6474f7..332c9eaeb 100644
--- a/src/acs/call-funcs.cpp
+++ b/src/acs/call-funcs.cpp
@@ -49,6 +49,7 @@
 #include "../r_draw.h"
 #include "../k_dialogue.hpp"
 #include "../k_hud.h"
+#include "../r_fps.h"
 
 #include "call-funcs.hpp"
 
@@ -2883,10 +2884,28 @@ bool CallFunc_SetSideProperty(ACSVM::Thread *thread, const ACSVM::Word *argV, AC
 		break; \
 	}
 
+			auto install_interpolator = [side]
+			{
+				if (side->acs_interpolated)
+					return;
+				side->acs_interpolated = true;
+				R_CreateInterpolator_SideScroll(nullptr, side);
+			};
+
 			switch (property)
 			{
-				PROP_INT(SIDE_PROP_XOFFSET, textureoffset)
-				PROP_INT(SIDE_PROP_YOFFSET, rowoffset)
+				case SIDE_PROP_XOFFSET:
+				{
+					side->textureoffset = static_cast< decltype(side->textureoffset) >(value);
+					install_interpolator();
+					break;
+				}
+				case SIDE_PROP_YOFFSET:
+				{
+					side->rowoffset = static_cast< decltype(side->rowoffset) >(value);
+					install_interpolator();
+					break;
+				}
 				PROP_TEXTURE(SIDE_PROP_TOPTEXTURE, toptexture)
 				PROP_TEXTURE(SIDE_PROP_BOTTOMTEXTURE, bottomtexture)
 				PROP_TEXTURE(SIDE_PROP_MIDTEXTURE, midtexture)
diff --git a/src/r_defs.h b/src/r_defs.h
index 305fcecde..089d41851 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -644,6 +644,9 @@ struct side_t
 	// We do not maintain names here.
 	INT32 toptexture, bottomtexture, midtexture;
 
+	// Interpolator installed? (R_CreateInterpolator_SideScroll)
+	boolean acs_interpolated;
+
 	// Linedef the sidedef belongs to
 	line_t *line;