diff --git a/doc/doxygen/lwip.Doxyfile b/doc/doxygen/lwip.Doxyfile
index b7e6bc93..750e0ad4 100644
--- a/doc/doxygen/lwip.Doxyfile
+++ b/doc/doxygen/lwip.Doxyfile
@@ -762,7 +762,7 @@ WARN_NO_PARAMDOC       = NO
 # a warning is encountered.
 # The default value is: NO.
 
-WARN_AS_ERROR          = NO
+WARN_AS_ERROR          = YES
 
 # The WARN_FORMAT tag determines the format of the warning messages that doxygen
 # can produce. The string should contain the $file, $line, and $text tags, which
diff --git a/doc/doxygen/lwip.Doxyfile.cmake.in b/doc/doxygen/lwip.Doxyfile.cmake.in
index 063c2887..4879d2e6 100644
--- a/doc/doxygen/lwip.Doxyfile.cmake.in
+++ b/doc/doxygen/lwip.Doxyfile.cmake.in
@@ -762,7 +762,7 @@ WARN_NO_PARAMDOC       = NO
 # a warning is encountered.
 # The default value is: NO.
 
-WARN_AS_ERROR          = NO
+WARN_AS_ERROR          = YES
 
 # The WARN_FORMAT tag determines the format of the warning messages that doxygen
 # can produce. The string should contain the $file, $line, and $text tags, which