diff --git a/src/Makefile_Eolian_Cxx_Helper.am b/src/Makefile_Eolian_Cxx_Helper.am
--- a/src/Makefile_Eolian_Cxx_Helper.am
+++ b/src/Makefile_Eolian_Cxx_Helper.am
@@ -14,5 +14,5 @@
 
 %.eo.impl.hh %.eo.hh: %.eo $(_EOLIAN_CXX_DEP)
 	$(AM_V_EOLCXX) \
-	$(MKDIR_P) $(dir $@); \
+	$(MKDIR_P) $(@D); \
 	$(EOLIAN_CXX) $(EOLIAN_FLAGS) -o $@ $<
diff --git a/src/Makefile_Eolian_Files_Helper.am b/src/Makefile_Eolian_Files_Helper.am
--- a/src/Makefile_Eolian_Files_Helper.am
+++ b/src/Makefile_Eolian_Files_Helper.am
@@ -7,20 +7,20 @@
 
 %.eo.c: %.eo ${_EOLIAN_GEN_DEP}
 	$(AM_V_EOL) \
-	$(MKDIR_P) $(dir $@); \
+	$(MKDIR_P) $(@D); \
 	$(EOLIAN_GEN) $(EOLIAN_FLAGS) $(EOLIAN_GEN_FLAGS) -gc -o c:$@ $<
 
 %.eo.h: %.eo ${_EOLIAN_GEN_DEP}
 	$(AM_V_EOL) \
-	$(MKDIR_P) $(dir $@); \
+	$(MKDIR_P) $(@D); \
 	$(EOLIAN_GEN) $(EOLIAN_FLAGS) $(EOLIAN_GEN_FLAGS) -gh -o h:$@ $<
 
 %.eot.h: %.eot ${_EOLIAN_GEN_DEP}
 	$(AM_V_EOL) \
-	$(MKDIR_P) $(dir $@); \
+	$(MKDIR_P) $(@D); \
 	$(EOLIAN_GEN) $(EOLIAN_FLAGS) $(EOLIAN_GEN_FLAGS) -gh -o h:$@ $<
 
 %.eo.legacy.h: %.eo ${_EOLIAN_GEN_DEP}
 	$(AM_V_EOL) \
-	$(MKDIR_P) $(dir $@); \
+	$(MKDIR_P) $(@D); \
 	$(EOLIAN_GEN) $(EOLIAN_FLAGS) $(EOLIAN_GEN_FLAGS) -gl -o l:$@ $<