diff --git a/backend/raster.c b/backend/raster.c
index 5705ed91..31dfa863 100644
--- a/backend/raster.c
+++ b/backend/raster.c
@@ -1165,7 +1165,8 @@ INTERNAL int plot_raster(struct zint_symbol *symbol, int rotate_angle, int file_
     int error;
 
 #ifdef NO_PNG
-    if (file_type == OUT_PNG_FILE) {
+    if (file_type == OUT_PNG_FILE) {
+		strcpy(symbol->errtxt, "660: PNG format disabled on compile time");
         return ZINT_ERROR_INVALID_OPTION;
     }
 #endif /* NO_PNG */