diff --git a/code/graphics/opengl/gropengldeferred.cpp b/code/graphics/opengl/gropengldeferred.cpp
index d7115500804..4d43ebdddc6 100644
--- a/code/graphics/opengl/gropengldeferred.cpp
+++ b/code/graphics/opengl/gropengldeferred.cpp
@@ -605,12 +605,16 @@ void gr_opengl_deferred_lighting_finish()
 			float u_scale, v_scale;
 			uint32_t array_index;
 			gr_set_texture_addressing(TMAP_ADDRESS_CLAMP);
-			gr_opengl_tcache_set(neb.getVolumeBitmapHandle(), TCACHE_TYPE_3DTEX, &u_scale, &v_scale, &array_index, 3);
-			glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+			// only set the filter parameter if the bind succeeded, or else it is applied to whatever
+			// texture was previously bound to this unit
+			if (gr_opengl_tcache_set(neb.getVolumeBitmapHandle(), TCACHE_TYPE_3DTEX, &u_scale, &v_scale, &array_index, 3)) {
+				glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+			}
 			if (neb.getNoiseActive()) {
 				gr_set_texture_addressing(TMAP_ADDRESS_WRAP);
-				gr_opengl_tcache_set(neb.getNoiseVolumeBitmapHandle(), TCACHE_TYPE_3DTEX, &u_scale, &v_scale, &array_index, 4);
-				glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+				if (gr_opengl_tcache_set(neb.getNoiseVolumeBitmapHandle(), TCACHE_TYPE_3DTEX, &u_scale, &v_scale, &array_index, 4)) {
+					glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+				}
 			}
 		}
 
diff --git a/code/graphics/opengl/gropengltexture.cpp b/code/graphics/opengl/gropengltexture.cpp
index b31c54945e8..9278a6abee5 100644
--- a/code/graphics/opengl/gropengltexture.cpp
+++ b/code/graphics/opengl/gropengltexture.cpp
@@ -978,7 +978,11 @@ int opengl_create_texture(int bitmap_handle, int bitmap_type, tcache_slot_opengl
 
 	auto base_level = 0;
 	auto resize = false;
-	if ( (Detail.hardware_textures < 4) && (bitmap_type != TCACHE_TYPE_AABITMAP) && (bitmap_type != TCACHE_TYPE_INTERFACE)
+	// User bitmaps are excluded from culling because they are streaming surfaces (e.g. animations and
+	// video) that are updated through gr_update_texture() with the bitmap's own dimensions each frame,
+	// which requires the texture to match the bitmap's size.
+	if ( (Detail.hardware_textures < 4) && (bm_get_type(bitmap_handle) != BM_TYPE_USER)
+		&& (bitmap_type != TCACHE_TYPE_AABITMAP) && (bitmap_type != TCACHE_TYPE_INTERFACE)
 		&& (bitmap_type != TCACHE_TYPE_CUBEMAP) && (bitmap_type != TCACHE_TYPE_3DTEX)
 		&& ((bitmap_type != TCACHE_TYPE_COMPRESSED) || ((bitmap_type == TCACHE_TYPE_COMPRESSED) && (max_levels > 1))) )
 	{
@@ -1565,6 +1569,13 @@ void gr_opengl_update_texture(int bitmap_handle, int bpp, const ubyte* data, int
 	auto t = bm_get_gr_info<tcache_slot_opengl>(bitmap_handle);
 	if(!t->texture_id)
 		return;
+
+	// This overwrites the texture with data at the bitmap's own size, so the texture must not have been
+	// culled when it was created (user bitmaps are exempt from texture detail culling for this reason).
+	Assertion((t->w == width) && (t->h == height),
+		"gr_opengl_update_texture() called for bitmap %s with %dx%d data, but its texture is %dx%d.",
+		bm_get_filename(bitmap_handle), width, height, t->w, t->h);
+
 	int byte_mult = (bpp >> 3);
 	int true_byte_mult = (t->bpp >> 3);
 	ubyte* texmem = NULL;