diff --git a/Makefile b/Makefile
index d80f5226..d0fb58fb 100644
--- a/Makefile
+++ b/Makefile
@@ -69,6 +69,7 @@ endif
 prefix := $(dir $(shell $(WHICH) gnatls))..
 
 GNATCOLL_PROJECTS := yes
+GNATCOLL_MINIMAL_ONLY := no
 BUILD         = PROD
 PROCESSORS    = 0
 ENABLE_SHARED = yes
@@ -111,7 +112,10 @@ else
 endif
 
 	$(PYTHON) $(SOURCE_DIR)/minimal/gnatcoll_minimal.gpr.py build $(INSTR_BUILD_OPTS) $(BUILD_ARGS)
+
+ifeq ($(GNATCOLL_MINIMAL_ONLY), no)
 	$(PYTHON) $(SOURCE_DIR)/core/gnatcoll_core.gpr.py build $(INSTR_BUILD_OPTS) $(BUILD_ARGS)
+endif
 
 ifeq ($(GNATCOLL_PROJECTS), yes)
 	$(PYTHON) $(SOURCE_DIR)/projects/gnatcoll_projects.gpr.py build $(INSTR_BUILD_OPTS) $(BUILD_ARGS)
diff --git a/minimal/src/getRSS.c b/minimal/src/getRSS.c
index 507a0548..cc739746 100644
--- a/minimal/src/getRSS.c
+++ b/minimal/src/getRSS.c
@@ -29,6 +29,10 @@
 
 #endif
 
+#elif defined(__vxworks)
+#include "vxWorks.h"
+#include <sys/time.h>
+
 #else
 #error "Cannot define getPeakRSS( ) or getCurrentRSS( ) for an unknown OS."
 #endif
diff --git a/minimal/src/gnatcoll_support.c b/minimal/src/gnatcoll_support.c
index a259944a..d620d119 100644
--- a/minimal/src/gnatcoll_support.c
+++ b/minimal/src/gnatcoll_support.c
@@ -30,6 +30,13 @@
 #include <windows.h>
 #endif
 
+#if defined (__vxworks)
+/* S_IREAD is not defined on VxWorks */
+#ifndef S_IREAD
+#define S_IREAD  (S_IRUSR | S_IRGRP | S_IROTH)
+#endif
+#endif
+
 #ifdef HAVE_SYSLOG
 #include <syslog.h>
 void