diff --git a/crypto/bn/Makefile.ssl b/crypto/bn/Makefile.ssl
index 29ca88ccd..3902c41c7 100644
--- a/crypto/bn/Makefile.ssl
+++ b/crypto/bn/Makefile.ssl
@@ -5,6 +5,7 @@
 DIR=	bn
 TOP=	../..
 CC=	cc
+CPP=    $(CC) -E
 INCLUDES= -I.. -I../../include
 CFLAG=-g
 INSTALL_PREFIX=
diff --git a/crypto/rc4/Makefile.ssl b/crypto/rc4/Makefile.ssl
index d3dff0f4a..53eac2064 100644
--- a/crypto/rc4/Makefile.ssl
+++ b/crypto/rc4/Makefile.ssl
@@ -5,6 +5,7 @@
 DIR=	rc4
 TOP=	../..
 CC=	cc
+CPP=    $(CC) -E
 INCLUDES=
 CFLAG=-g
 INSTALL_PREFIX=
diff --git a/crypto/sha/Makefile.ssl b/crypto/sha/Makefile.ssl
index d30e7244c..0e6e7b894 100644
--- a/crypto/sha/Makefile.ssl
+++ b/crypto/sha/Makefile.ssl
@@ -5,6 +5,7 @@
 DIR=    sha
 TOP=    ../..
 CC=     cc
+CPP=    $(CC) -E
 INCLUDES=
 CFLAG=-g
 INSTALL_PREFIX=