diff --git a/lib/librte_acl/Makefile b/lib/librte_acl/Makefile
index 59767920a..bce78813b 100644
--- a/lib/librte_acl/Makefile
+++ b/lib/librte_acl/Makefile
@@ -34,8 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_acl.a
 
-CFLAGS += -O3
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_acl_version.map
 
diff --git a/lib/librte_bitratestats/Makefile b/lib/librte_bitratestats/Makefile
index 58a20ea09..26a3f4908 100644
--- a/lib/librte_bitratestats/Makefile
+++ b/lib/librte_bitratestats/Makefile
@@ -34,7 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_bitratestats.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_bitratestats_version.map
 
diff --git a/lib/librte_cmdline/Makefile b/lib/librte_cmdline/Makefile
index 644f68e47..9dd75f2d2 100644
--- a/lib/librte_cmdline/Makefile
+++ b/lib/librte_cmdline/Makefile
@@ -34,7 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_cmdline.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_cmdline_version.map
 
diff --git a/lib/librte_distributor/Makefile b/lib/librte_distributor/Makefile
index b417ee7be..a51d7c8b2 100644
--- a/lib/librte_distributor/Makefile
+++ b/lib/librte_distributor/Makefile
@@ -34,8 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_distributor.a
 
-CFLAGS += -O3
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_distributor_version.map
 
diff --git a/lib/librte_eal/linuxapp/eal/Makefile b/lib/librte_eal/linuxapp/eal/Makefile
index 90bca4d68..f5eee1c6a 100644
--- a/lib/librte_eal/linuxapp/eal/Makefile
+++ b/lib/librte_eal/linuxapp/eal/Makefile
@@ -41,7 +41,13 @@ LIBABIVER := 5
 
 VPATH += $(RTE_SDK)/lib/librte_eal/common
 
-CFLAGS += -I$(SRCDIR)/include
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR)/include $(CFLAGS)
 CFLAGS += -I$(RTE_SDK)/lib/librte_eal/common
 CFLAGS += -I$(RTE_SDK)/lib/librte_eal/common/include
 CFLAGS += $(WERROR_FLAGS) -O3
diff --git a/lib/librte_efd/Makefile b/lib/librte_efd/Makefile
index b9277bc5d..b169e3240 100644
--- a/lib/librte_efd/Makefile
+++ b/lib/librte_efd/Makefile
@@ -34,8 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_efd.a
 
-CFLAGS += -O3
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_efd_version.map
 
diff --git a/lib/librte_gro/Makefile b/lib/librte_gro/Makefile
index 747eeec9e..4a9f12d85 100644
--- a/lib/librte_gro/Makefile
+++ b/lib/librte_gro/Makefile
@@ -34,8 +34,15 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_gro.a
 
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
 CFLAGS += -O3
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
+CFLAGS += $(WERROR_FLAGS)
 
 EXPORT_MAP := rte_gro_version.map
 
diff --git a/lib/librte_hash/Makefile b/lib/librte_hash/Makefile
index 9cf13a045..677d494e7 100644
--- a/lib/librte_hash/Makefile
+++ b/lib/librte_hash/Makefile
@@ -34,8 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_hash.a
 
-CFLAGS += -O3
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_hash_version.map
 
diff --git a/lib/librte_ip_frag/Makefile b/lib/librte_ip_frag/Makefile
index 4e693bf8f..de45ec2d3 100644
--- a/lib/librte_ip_frag/Makefile
+++ b/lib/librte_ip_frag/Makefile
@@ -34,8 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_ip_frag.a
 
-CFLAGS += -O3
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_ipfrag_version.map
 
diff --git a/lib/librte_jobstats/Makefile b/lib/librte_jobstats/Makefile
index 561a0678c..57329b18e 100644
--- a/lib/librte_jobstats/Makefile
+++ b/lib/librte_jobstats/Makefile
@@ -34,8 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_jobstats.a
 
-CFLAGS += -O3
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_jobstats_version.map
 
diff --git a/lib/librte_kni/Makefile b/lib/librte_kni/Makefile
index 70f1ca8f6..130d6fd74 100644
--- a/lib/librte_kni/Makefile
+++ b/lib/librte_kni/Makefile
@@ -34,7 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_kni.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -fno-strict-aliasing
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3 -fno-strict-aliasing
 
 EXPORT_MAP := rte_kni_version.map
 
diff --git a/lib/librte_kvargs/Makefile b/lib/librte_kvargs/Makefile
index 564dd3102..7c332c110 100644
--- a/lib/librte_kvargs/Makefile
+++ b/lib/librte_kvargs/Makefile
@@ -36,7 +36,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_kvargs.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_kvargs_version.map
 
diff --git a/lib/librte_latencystats/Makefile b/lib/librte_latencystats/Makefile
index eaacbb731..46a8ecd34 100644
--- a/lib/librte_latencystats/Makefile
+++ b/lib/librte_latencystats/Makefile
@@ -33,7 +33,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_latencystats.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 LDLIBS += -lm
 LDLIBS += -lpthread
 
diff --git a/lib/librte_lpm/Makefile b/lib/librte_lpm/Makefile
index 32be46b3b..6a97fdc97 100644
--- a/lib/librte_lpm/Makefile
+++ b/lib/librte_lpm/Makefile
@@ -34,8 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_lpm.a
 
-CFLAGS += -O3
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_lpm_version.map
 
diff --git a/lib/librte_mbuf/Makefile b/lib/librte_mbuf/Makefile
index 548273054..4d51191ee 100644
--- a/lib/librte_mbuf/Makefile
+++ b/lib/librte_mbuf/Makefile
@@ -34,7 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_mbuf.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_mbuf_version.map
 
diff --git a/lib/librte_mempool/Makefile b/lib/librte_mempool/Makefile
index 7b5bdfee7..33678192f 100644
--- a/lib/librte_mempool/Makefile
+++ b/lib/librte_mempool/Makefile
@@ -34,7 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_mempool.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_mempool_version.map
 
diff --git a/lib/librte_metrics/Makefile b/lib/librte_metrics/Makefile
index d4990e839..195bd4d56 100644
--- a/lib/librte_metrics/Makefile
+++ b/lib/librte_metrics/Makefile
@@ -34,7 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_metrics.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_metrics_version.map
 
diff --git a/lib/librte_net/Makefile b/lib/librte_net/Makefile
index 56727c4df..a08a7dd8b 100644
--- a/lib/librte_net/Makefile
+++ b/lib/librte_net/Makefile
@@ -33,7 +33,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 
 LIB = librte_net.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_net_version.map
 LIBABIVER := 1
diff --git a/lib/librte_pdump/Makefile b/lib/librte_pdump/Makefile
index 1c03bcbb7..8923d7499 100644
--- a/lib/librte_pdump/Makefile
+++ b/lib/librte_pdump/Makefile
@@ -34,8 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_pdump.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
-CFLAGS += -D_GNU_SOURCE
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3 -D_GNU_SOURCE
 LDLIBS += -lpthread
 
 EXPORT_MAP := rte_pdump_version.map
diff --git a/lib/librte_power/Makefile b/lib/librte_power/Makefile
index 06cd10e86..b76ad689e 100644
--- a/lib/librte_power/Makefile
+++ b/lib/librte_power/Makefile
@@ -34,7 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_power.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -fno-strict-aliasing
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3 -fno-strict-aliasing
 
 EXPORT_MAP := rte_power_version.map
 
diff --git a/lib/librte_reorder/Makefile b/lib/librte_reorder/Makefile
index 4e44e72f0..51b5d490d 100644
--- a/lib/librte_reorder/Makefile
+++ b/lib/librte_reorder/Makefile
@@ -34,8 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_reorder.a
 
-CFLAGS += -O3
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_reorder_version.map
 
diff --git a/lib/librte_ring/Makefile b/lib/librte_ring/Makefile
index 3e2f4b873..e5248a2c1 100644
--- a/lib/librte_ring/Makefile
+++ b/lib/librte_ring/Makefile
@@ -34,7 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_ring.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during paralle
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_ring_version.map
 
diff --git a/lib/librte_timer/Makefile b/lib/librte_timer/Makefile
index 03a15390e..0c57cc6d3 100644
--- a/lib/librte_timer/Makefile
+++ b/lib/librte_timer/Makefile
@@ -34,7 +34,14 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_timer.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during parallel
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3
 
 EXPORT_MAP := rte_timer_version.map
 
diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile
index 4a116fe31..ef0d86990 100644
--- a/lib/librte_vhost/Makefile
+++ b/lib/librte_vhost/Makefile
@@ -38,7 +38,14 @@ EXPORT_MAP := rte_vhost_version.map
 
 LIBABIVER := 4
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -D_FILE_OFFSET_BITS=64
+# Include the source dir first, so that headers paths are always picked
+# from there. By including it last race conditions might happen during parallel
+# builds, and headers might be already installed in RTE_OUT/include when the
+# variable is recursively expanded, thus causing GCC to sometimes use the
+# SRCDIR path and sometimes the RTE_OUT/include, making the builds not
+# reproducible.
+CFLAGS := -I$(SRCDIR) $(CFLAGS)
+CFLAGS += $(WERROR_FLAGS) -O3 -D_FILE_OFFSET_BITS=64
 CFLAGS += -I vhost_user
 LDLIBS += -lpthread
 
