diff --git a/common/include/u_mem.h b/common/include/u_mem.h
index 6b9df8d67..50bf8bffd 100644
--- a/common/include/u_mem.h
+++ b/common/include/u_mem.h
@@ -91,12 +91,12 @@ public:
 	}
 };
 
-template <typename T>
-class RAIIdmem : public std::unique_ptr<T, RAIIdmem_deleter<T>>
+template <typename U, typename T = typename tt::remove_extent<U>::type>
+class RAIIdmem : public std::unique_ptr<U, RAIIdmem_deleter<T>>
 {
 	static_assert(tt::is_pod<T>::value, "RAIIdmem cannot manage non-POD");
 public:
-	DXX_INHERIT_CONSTRUCTORS(RAIIdmem, std::unique_ptr<T, RAIIdmem_deleter<T>>);
+	DXX_INHERIT_CONSTRUCTORS(RAIIdmem, std::unique_ptr<U, RAIIdmem_deleter<T>>);
 	operator T*() const
 #ifdef DXX_HAVE_CXX11_REF_QUALIFIER
 		&
@@ -110,14 +110,14 @@ template <typename T>
 T *MALLOC(RAIIdmem<T> &r, std::size_t count, const char *var, const char *file, unsigned line)
 {
 	T *p;
-	return r = RAIIdmem<T>(MALLOC<T>(p, count, var, file, line));
+	return r.reset(MALLOC<T>(p, count, var, file, line)), p;
 }
 
 template <typename T>
 T *CALLOC(RAIIdmem<T> &r, std::size_t count, const char *var, const char *file, unsigned line)
 {
 	T *p;
-	return r = RAIIdmem<T>(CALLOC<T>(p, count, var, file, line));
+	return r.reset(CALLOC<T>(p, count, var, file, line)), p;
 }
 
 #define MALLOC( var, type, count )	(MALLOC<type>(var, (count)*sizeof(type),#var, __FILE__,__LINE__ ))
diff --git a/similar/main/terrain.cpp b/similar/main/terrain.cpp
index b547198b9..ea8ba28ee 100644
--- a/similar/main/terrain.cpp
+++ b/similar/main/terrain.cpp
@@ -50,7 +50,7 @@ COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
 
 static int grid_w,grid_h;
 
-static ubyte *height_array;
+static RAIIdmem<ubyte[]> height_array;
 static std::unique_ptr<uint8_t[]> light_array;
 
 #define HEIGHT(_i,_j) (height_array[(_i)*grid_w+(_j)])
@@ -327,8 +327,7 @@ void render_terrain(const vms_vector &org_point,int org_2dx,int org_2dy)
 
 void free_height_array()
 {
-	if (height_array)
-		d_free(height_array);
+	height_array.reset();
 }
 
 void load_terrain(const char *filename)
@@ -342,17 +341,13 @@ void load_terrain(const char *filename)
 	if (iff_error != IFF_NO_ERROR) {
 		Error("File %s - IFF error: %s",filename,iff_errormsg(iff_error));
 	}
-
-	if (height_array)
-		d_free(height_array);
-
 	grid_w = height_bitmap.bm_w;
 	grid_h = height_bitmap.bm_h;
 
 	Assert(grid_w <= GRID_MAX_SIZE);
 	Assert(grid_h <= GRID_MAX_SIZE);
 
-	height_array = height_bitmap.get_bitmap_data();
+	height_array.reset(height_bitmap.get_bitmap_data());
 
 	max_h=0; min_h=255;
 	for (i=0;i<grid_w;i++)