diff --git a/ADApp/pluginSrc/Makefile b/ADApp/pluginSrc/Makefile
index 471356d63..ecdb5c614 100644
--- a/ADApp/pluginSrc/Makefile
+++ b/ADApp/pluginSrc/Makefile
@@ -216,7 +216,7 @@ ifdef HDF5_INCLUDE
 endif
 
 ifdef SZIP_INCLUDE
-  USR_INCLUDES += $(addprefix -I, $(HDF5_INCLUDE))
+  USR_INCLUDES += $(addprefix -I, $(SZIP_INCLUDE))
 endif
 
 ifdef XML2_INCLUDE