diff --git a/Makefile.conf b/Makefile.conf
index 02e0872..8e567e0 100644
--- a/Makefile.conf
+++ b/Makefile.conf
@@ -25,13 +25,8 @@ ifeq ($(PLATFORM),linux)
 endif
 
 
-# Old versions of a Java distribution have a `javah` binary, new versions do not. This checks whether or not `javah` can be found in the Java distribution found in the directory `$JAVA_HOME`.
-DUMMY:=$(shell which $(JAVA_HOME)/bin/javah)
-ifeq ($(.SHELLSTATUS),0)
-    OLD_JAVA=true
-endif
-
 JAVAC_CMD=javac -encoding UTF-8
+JAVAH_CMD=javah -encoding UTF-8
 
 ######### Overrides from the config file(s) #########
 ifneq ("$(wildcard $(HERE)local.conf)","")
@@ -51,6 +46,12 @@ ifndef JAVA_HOME
     $(error JAVA_HOME is not set!)
 endif
 
+# Old versions of a Java distribution have a `javah` binary, new versions do not. This checks whether or not `javah` can be found in the Java distribution found in the directory `$JAVA_HOME`.
+DUMMY:=$(shell which $(JAVA_HOME)/bin/javah)
+ifeq ($(.SHELLSTATUS),0)
+    OLD_JAVA=true
+endif
+
 JAVA_BIN_DIR=$(JAVA_HOME)/bin
 
 ######### C and C++ #########
@@ -75,3 +76,14 @@ endif
 ### YML_PATH is needed in the environment of every call to a program of the YML2 distribution
 export YML_PATH=$(YML2_PATH)
 
+# BEGIN // kryptic hack to to replace a space with a newline
+# $(subst ${ },${space}, whatever)
+null :=
+space := ${null} ${null}
+${space} := ${space}
+
+define \n
+
+
+endef
+# END // kryptic hack to to replace a space with a newline
diff --git a/src/Makefile b/src/Makefile
index 08dc37b..926d660 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -50,9 +50,9 @@ CXX_DIR=cxx/
 JAVA_DIR=java/
 JAVA_PKG_BASENAME=foundation/pEp/jniadapter/
 
-JAVA_PKG_ROOT=$(JAVA_DIR)/$(JAVA_PKG_BASENAME)
-JAVA_BUILD_ROOT=$(BUILD_ROOT)/$(JAVA_DIR)
-OBJ_DIR=$(BUILD_ROOT)/$(CXX_DIR)
+JAVA_PKG_ROOT=$(JAVA_DIR)$(JAVA_PKG_BASENAME)
+JAVA_BUILD_ROOT=$(BUILD_ROOT)$(JAVA_DIR)
+OBJ_DIR=$(BUILD_ROOT)$(CXX_DIR)
 
 
 # for "make clean" only
@@ -142,9 +142,11 @@ $(OBJECTS): $(BUILD_ROOT)%.o: %.cc
 # --------- Generate JNI headers ----------
 gen-jni-headers: codegen $(JNI_GENERATED_HH)
 
+# "new" javac -h accepts list of java files
+# While "old" (Java 8) javah needs a list of java classes (e.g. foundation.pEp.jniadapter.Message)
 $(JNI_GENERATED_HH):
 ifdef OLD_JAVA
-	cd $(JAVA_DIR);$(JAVA_BIN_DIR)/javah -d ../$(JAVA_BUILD_ROOT) $(subst /,.,$(subst .java,,$<))
+	cd $(JAVA_BUILD_ROOT)/;$(JAVA_BIN_DIR)/$(JAVAH_CMD) -d ../../src/$(CXX_DIR) $(subst ${ },${space}\${\n}, $(subst /,.,$(subst $(JAVA_BUILD_ROOT),,$(basename $(sort $(wildcard $(JAVA_BUILD_ROOT)$(JAVA_PKG_BASENAME)*.class/))))))
 else
 	cd $(JAVA_DIR);$(JAVA_BIN_DIR)/$(JAVAC_CMD) -d ../$(JAVA_BUILD_ROOT) -h ../$(CXX_DIR)/ $(JAVA_PKG_BASENAME)/*.java
 endif