diff --git a/pppd/Makefile.linux b/pppd/Makefile.linux
index 22837c5..6f6fff5 100644
--- a/pppd/Makefile.linux
+++ b/pppd/Makefile.linux
@@ -111,8 +111,8 @@ endif
 
 # EAP SRP-SHA1
 ifdef USE_SRP
-CFLAGS	+= -DUSE_SRP -DOPENSSL -I/usr/local/ssl/include
-LIBS	+= -lsrp -L/usr/local/ssl/lib
+CFLAGS	+= -DUSE_SRP -DOPENSSL -I@openssl_dev@/include/openssl
+LIBS	+= -lsrp -L@openssl_lib@/lib
 NEEDCRYPTOLIB = y
 TARGETS	+= srp-entry
 EXTRAINSTALL = $(INSTALL) -c -m 555 srp-entry $(BINDIR)/srp-entry
@@ -143,7 +143,7 @@ CFLAGS   += -DHAS_SHADOW
 #LIBS     += -lshadow $(LIBS)
 endif
 
-ifeq ($(shell echo '\#include <crypt.h>' | $(CC) -E - >/dev/null 2>&1 && echo yes),yes)
+ifneq ($(wildcard @glibc@/include/crypt.h),)
 CFLAGS  += -DHAVE_CRYPT_H=1
 LIBS	+= -lcrypt
 endif
@@ -155,7 +155,7 @@ endif
 
 ifdef NEEDDES
 ifndef USE_CRYPT
-CFLAGS   += -I$(shell $(CC) --print-sysroot)/usr/include/openssl
+CFLAGS   += -I@openssl_dev@/include/openssl
 NEEDCRYPTOLIB = y
 else
 CFLAGS   += -DUSE_CRYPT=1