diff --git a/debian/rules b/debian/rules
index 066cfa078d..54b4dac04e 100755
--- a/debian/rules
+++ b/debian/rules
@@ -49,6 +49,7 @@ DEB_HOST_GNU_TYPE   ?= $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
 DEB_BUILD_GNU_TYPE  ?= $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
 
 CFLAGS = -ggdb
+MOD_CFLAGS = -ggdb
 
 FEATURES = --enable-core-libedit-support --enable-core-odbc-support --with-libcurl --with-openssl