diff --git a/prism/src/simulator/Makefile b/prism/src/simulator/Makefile
index d616ac16..39550373 100644
--- a/prism/src/simulator/Makefile
+++ b/prism/src/simulator/Makefile
@@ -21,7 +21,7 @@ LIBRARIES = \
 -L$(PRISM_DIR_REL)/$(LIB_DIR) \
 -lm
 
-JAVA_FILES = $(shell find . -name '*.java')
+JAVA_FILES = $(wildcard *.java networking/*.java)
 CLASS_FILES = $(JAVA_FILES:%.java=$(PRISM_DIR_REL)/$(CLASSES_DIR)/$(THIS_DIR)/%.class)
 
 CC_FILES = $(wildcard *.cc)
diff --git a/prism/src/userinterface/Makefile b/prism/src/userinterface/Makefile
index fe509968..e5dcd880 100644
--- a/prism/src/userinterface/Makefile
+++ b/prism/src/userinterface/Makefile
@@ -10,7 +10,7 @@
 THIS_DIR = userinterface
 PRISM_DIR_REL = ../..
 
-JAVA_FILES = $(shell find . -name '*.java')
+JAVA_FILES = $(wildcard *.java model/*.java model/computation/*.java model/pepaModel/*.java model/graphicModel/*.java util/*.java simulator/*.java simulator/networking/*.java properties/*.java properties/computation/*.java log/*.java)
 CLASS_FILES = $(JAVA_FILES:%.java=$(PRISM_DIR_REL)/$(CLASSES_DIR)/$(THIS_DIR)/%.class)
 
 default: all