diff --git a/externals/OSCx/src/Makefile b/externals/OSCx/src/Makefile
index 6b5753b52d083729c94122078e0fc47d66345da0..e5c4da7e9b8c81b4b92dceb2e52ffce843988ff8 100644
--- a/externals/OSCx/src/Makefile
+++ b/externals/OSCx/src/Makefile
@@ -21,7 +21,7 @@ LIBS = -L../../../pd/bin -lc -lm
 LIBOSC = ../libOSC/libOSC.a
 
 CFLAGS = -g -O2 -DUNIX -Wall -Wimplicit -Wunused -Wmissing-prototypes -O1 -fPIC -I../libOSC -I../../pd/src -I../../../pd/src -I../src
-INCLUDES = -I../libOSC -I../../pd/src -I../../../pd/src -I../src
+INCLUDES = -I../libOSC -I../../pd/src -I../../../pd/src -I../src -I/usr/include/tirpc
 LDFLAGS = -Wl,--export-dynamic -shared
 
 prefix=/usr/local
diff --git a/externals/OSCx/src/Makefile.in b/externals/OSCx/src/Makefile.in
index 41032de64e53e452889eecfb1b1b4651fbfc3afa..2a9089ea4eb5d51bce79c849fae626198545dc2c 100644
--- a/externals/OSCx/src/Makefile.in
+++ b/externals/OSCx/src/Makefile.in
@@ -21,7 +21,7 @@ LIBS = @LIBS@
 LIBOSC = ../libOSC/@LIBOSC@
 
 CFLAGS = @CFLAGS@
-INCLUDES = @INCLUDES@
+INCLUDES = @INCLUDES@ -I/usr/include/tirpc
 LDFLAGS = @LDFLAGS@
 
 prefix=@prefix@