diff --git a/prism/Makefile b/prism/Makefile
index 47298021..b89f0f46 100644
--- a/prism/Makefile
+++ b/prism/Makefile
@@ -434,8 +434,10 @@ tarcf:
 	echo Building tar file "../"$$TARCF_DIR".tar.gz" && \
 	(cd ..; tar cfz $$TARCF_DIR".tar.gz" $$TARCF_DIR)
 
+PRISM_CLASSPATH = "$(CLASSES_DIR)$(CLASSPATHSEP)$(LIB_DIR)/jcommon.jar$(CLASSPATHSEP)$(LIB_DIR)/jfreechart.jar$(CLASSPATHSEP)$(LIB_DIR)/epsgraphics.jar"
+
 javadoc:
-	@JAVADOC_DIRS=`echo $(MAKE_DIRS) | sed 's/\//./g' | sed 's/ /:/g'` && \mkdir -p javadoc; javadoc -d javadoc -classpath $(SRC_DIR) -subpackages $$JAVADOC_DIRS
+	@JAVADOC_DIRS=`echo $(MAKE_DIRS) | sed 's/\//./g' | sed 's/ /:/g'` && \mkdir -p javadoc; javadoc -d javadoc -classpath $(SRC_DIR)$(CLASSPATHSEP)$(PRISM_CLASSPATH) -subpackages $$JAVADOC_DIRS
 
 clean: checks
 	@(for dir in $(MAKE_DIRS); do \